CHEMINF terms
type: Ontology
version IRI: cheminf
imports: reused-terms
abstract: The CHEMINF module of SSbD Core Ontology providing a taxonomy for chemical descriptors.
introduction: This module is a part of the [SSbD Core Ontology](https://ssbd-ontology.github.io/core/widoco/index-en.html).A *descriptor* or *indicator* is a property that provides information about the state of a system. It simplifies complex realities into measurable values that can guide decisions. A service for browsing and searching CHEMINF can be found [here](https://ontobee.org/ontology/CHEMINF?iri=http://semanticscience.org/resource/CHEMINF_000123).

is about
type: ObjectProperty
IAO_0000112: This document is about information artifacts and their representations
IAO_0000114: IAO_0000125
IAO_0000115: A (currently) primitive relation that relates an information artifact to an entity.
IAO_0000116: 7/6/2009 Alan Ruttenberg. Following discussion with Jonathan Rees, and introduction of "mentions" relation. Weaken the is_about relationship to be primitive. We will try to build it back up by elaborating the various subproperties that are more precisely defined. Some currently missing phenomena that should be considered "about" are predications - "The only person who knows the answer is sitting beside me" , Allegory, Satire, and other literary forms that can be topical without explicitly mentioning the topic.
IAO_0000117: person:Alan Ruttenberg
IAO_0000119: Smith, Ceusters, Ruttenberg, 2000 years of philosophy
preferred label: isAbout

participates in
type: ObjectProperty
IAO_0000111: participates in
IAO_0000112: this blood clot participates in this blood coagulation
IAO_0000112: this input material (or this output material) participates in this process
IAO_0000112: this investigator participates in this investigation
IAO_0000115: a relation between a continuant and a process, in which the continuant is somehow involved in the process
IAO_0000118: participates_in
has alternative id: OBO_REL:0000020
has OBO namespace: relationship
label: participates_in
preferred label: participatesIn

has value
type: DatatypeProperty
preferred label: hasValue

MolecularEntity
type: Class
subclass of: chemical entity
has alternative id: CHEBI:23367
definition: Molecular entity

atom
type: Class
subclass of: chemical entity
has alternative id: CHEBI:33250
preferred label: Atom

PolyatomicEntity
type: Class
subclass of: MolecularEntity
has alternative id: CHEBI:36357
definition: Polyatomic entity

chemical entity
type: Class
has alternative id: CHEBI:24431
has alternative id: obo:24431
definition: A chemical entity is any molecular entity or chemical substance.
preferred label: ChemicalEntity

molar refractivity
type: Class
subclass of: ChargeDelocalizationDescriptor
definition: Molar refractviity is a measure of the total polarizability of a mole of a substance and is dependent on the temperature, the index of refraction, and the pressure.
preferred label: MolarRefractivity

atomic polarizability sum
type: Class
subclass of: ChargeDelocalizationDescriptor
definition: atomic polarizability sum is the sum of the atomic polarizabilities (including implicit hydrogens).
preferred label: AtomicPolarizabilitySum

partial positive surface area
type: Class
subclass of: surface area descriptor
alternative label: PPSA-1
definition: sum of surface area on positive parts of molecule
preferred label: PartialPositiveSurfaceArea

PPSA-2
type: Class
subclass of: surface area descriptor
definition: partial positive surface area * total positive charge on the molecule
preferred label: PPSAMinus2

RSStereochemicalDescriptor
type: Class
subclass of: absolute configuration stereochemical descriptor
definition: RS stereochemical descriptor

RStereochemicalDescriptor
type: Class
subclass of: RSStereochemicalDescriptor
disjoint with: SStereochemicalDescriptor
definition: R stereochemical descriptor

canonical SMILES descriptor
type: Class
subclass of: SMILES descriptor
definition: A canonical SMILES descriptor is a SMILES descriptor that is produced using a canonicalization algorithm which results in one special generic SMILES among all valid possibilities.
preferred label: CanonicalSMILESDescriptor

charge weighted partial positive surface area
type: Class
subclass of: surface area descriptor
alternative label: PPSA-3
definition: charge weighted partial positive surface area
preferred label: ChargeWeightedPartialPositiveSurfaceArea

atomic order
type: Class
subclass of: positional descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
subclass of: Restriction
  on property: has value
  some values from: int
definition: Atomic order is an atomic descriptor that specifies the ordinal position of an atom.
preferred label: AtomicOrder

partial negative surface area
type: Class
subclass of: surface area descriptor
alternative label: PNSA-1
definition: sum of surface area on negative parts of molecule
preferred label: PartialNegativeSurfaceArea

PNSA-2
type: Class
subclass of: surface area descriptor
definition: partial negative surface area * total negative charge on the molecule
preferred label: PNSAMinus2

energetic descriptor
type: Class
subclass of: chemical descriptor
definition: An energetic descriptor is a chemical descriptor which captures information about some aspect of the energetic behaviour of a chemical entity.
preferred label: EnergeticDescriptor

SMILES descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A SMILES descriptor is a structure descriptor that denotes a molecular structure as a graph.
preferred label: SMILESDescriptor

SMARTS descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A SMARTS descriptor is a molecular structure descriptor that conforms to the SMARTS specification.
preferred label: SMARTSDescriptor

physical descriptor
type: Class
subclass of: chemical descriptor
definition: A physical descriptor is a chemical descriptor which describes some physical property (quality or disposition) of a chemical entity.
preferred label: PhysicalDescriptor

stereochemical descriptor
type: Class
subclass of: chemical descriptor
definition: A stereochemical descriptor is a chemical descriptor which describes some aspect of the three dimensional structure of a chemical entity.
preferred label: StereochemicalDescriptor

isomeric SMILES descriptor
type: Class
subclass of: SMILES descriptor
definition: an isomeric SMILES descriptor is a SMILES descriptor that written with isotopic and chiral specifications.
preferred label: IsomericSMILESDescriptor

SStereochemicalDescriptor
type: Class
subclass of: RSStereochemicalDescriptor
definition: S stereochemical descriptor

positional descriptor
type: Class
subclass of: chemical descriptor
definition: A positional descriptor is a chemical descriptor which describes some aspect of the position, or location of a chemical entity, or of the relative parts of a chemical entity with respct to one another.
preferred label: PositionalDescriptor

molecular formula
type: Class
subclass of: ConstitutionalDescriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A molecular formula is a structure descriptor which identifies each constituent element by its chemical symbol and indicates the number of atoms of each element found in each discrete molecule of that compound.
preferred label: MolecularFormula

molecular entity name
type: Class
subclass of: identifying descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: An information entity about a molecular entity which serves to name that molecular entity.
preferred label: MolecularEntityName

preferred name
type: Class
subclass of: molecular entity name
definition: A preferred name is a molecular entity name which is preferred, or recommended, for usage in textual annotations referring to that molecular entity.
preferred label: PreferredName

zagreb index
type: Class
subclass of: count descriptor
definition: The sum of the squared atom degrees of all heavy atoms.
preferred label: ZagrebIndex

PlusMinusStereochemicalDescriptor
type: Class
subclass of: relative configuration stereochemical descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: +/- stereochemical descriptor

PlusStereochemicalDescriptor
type: Class
subclass of: PlusMinusStereochemicalDescriptor
disjoint with: MinusStereochemicalDescriptor
definition: + stereochemical descriptor

MinusStereochemicalDescriptor
type: Class
subclass of: PlusMinusStereochemicalDescriptor
definition: - stereochemical descriptor

DLStereochemicalDescriptor
type: Class
subclass of: relative configuration stereochemical descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: DL stereochemical descriptor

DStereochemicalDescriptor
type: Class
subclass of: DLStereochemicalDescriptor
disjoint with: LStereochemicalDescriptor
definition: D stereochemical descriptor

LStereochemicalDescriptor
type: Class
subclass of: DLStereochemicalDescriptor
definition: L stereochemical descriptor

chemical connectivity table
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A chemical connectivity table is a structure descriptor which consists of a connection table representing bonds between atoms in a molecular entity.
preferred label: ChemicalConnectivityTable

aromaticity descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: An aromaticity descriptor is a chemical descriptor which indicates the aromaticity of a molecular entity.
preferred label: AromaticityDescriptor

file
type: Class
subclass of: physical descriptor
creator: http://orcid.org/0000-0003-3465-8786
date: 2017-02-09T14:29:12+00:00
label: melt mass flow rate
preferred label: File
preferred label: MeltMassFlowRate

MOLfile
type: Class
subclass of: file
definition: A MOLfile is a file which contains a MOLfile encoding of a chemical structure representation. It is the concretization of a MOLfile descriptor.

InChIKey
type: Class
subclass of: identifying descriptor
subclass of: Restriction
  on property: is about
  some values from: PolyatomicEntity

dimensional extent descriptor
type: Class
subclass of: geometric descriptor
definition: A dimensional extent descriptor is a physical property descriptor which describes some measurable length, area or volume aspect of a chemical entity.
preferred label: DimensionalExtentDescriptor

identifying descriptor
type: Class
subclass of: chemical descriptor
definition: An identifying descriptor is a chemical descriptor which provides an identifier for the chemical entity it is about, which in most cases should aim to be unique and easy to use as an unambiguous reference for the chemical entity.
preferred label: IdentifyingDescriptor

bond order descriptor
type: Class
subclass of: geometric descriptor
definition: A bond order descriptor is a descriptor associated with a bond in a chemical entity which indicates the order of the bond (single, double or triple).
preferred label: BondOrderDescriptor

QSAR descriptor
type: Class
subclass of: chemical descriptor
has alternative id: BODO:Descriptor
comment: NOTE: QSAR descriptors are often just called 'chemical descriptor' or 'molecular descriptor' in the cheminformatics community.
definition: A Quantitative Structure Activity Relationship (QSAR) descriptor is a chemical descriptor which gives a numeric, quantitative value which is believed to be associated with some aspect of the chemical or biological activity of the chemical entity.
preferred label: QSARDescriptor

functional group descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A functional group descriptor is a structural descriptor which describes specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
preferred label: FunctionalGroupDescriptor

neutron count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: The (integer) number of neutrons in the atoms nucleus.
preferred label: NeutronCount

proton count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: The (integer) number of protons in the atoms nucleus.
preferred label: ProtonCount

CisMinustransStereochemicalDescriptor
type: Class
subclass of: relative configuration stereochemical descriptor
definition: Cis-trans stereochemical descriptor
definition: Descriptors which show the relationship between two ligands attached to separate atoms that are connected by a double bond or are contained in a ring. The two ligands are said to be located cis to each other if they lie on the same side of a plane. If they are on opposite sides, their relative position is described as trans. The appropriate reference plane of a double bond is perpendicular to that of the relevant s-bonds and passes through the double bond.[source:IUPAC Gold Book - http://goldbook.iupac.org/C01092.html]

CisStereochemicalDescriptor
type: Class
subclass of: CisMinustransStereochemicalDescriptor
definition: Cis stereochemical descriptor

TransStereochemicalDescriptor
type: Class
subclass of: CisMinustransStereochemicalDescriptor
definition: Trans stereochemical descriptor

MassDescriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: Mass descriptor

AtomicMassDescriptor
type: Class
subclass of: MassDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: Atomic mass descriptor

structural descriptor
type: Class
subclass of: chemical descriptor
definition: A structural descriptor is a chemical descriptor which is about some aspect of the molecular structure (composition) of a chemical entity.
preferred label: StructuralDescriptor

ElectronicDescriptor
type: Class
subclass of: chemical descriptor
definition: Electronic descriptor

MolecularMassDescriptor
type: Class
subclass of: MassDescriptor
subclass of: Restriction
  on property: is about
  some values from: PolyatomicEntity
IAO_0000115: The mass of a molecule calculated according to some assumption about the isotopic identity of the atoms constituting it.
IAO_0000117: Person: Colin Batchelor
definition: Molecular mass descriptor

atomic degree
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: The integer number of non-H substituents of an atom.
preferred label: AtomicDegree

topological descriptor
type: Class
subclass of: chemical descriptor
definition: A topological descriptor is a chemical descriptor which pertains to spatial properties of a geometric object that are preserved under continuous deformations of objects, for example, deformations that involve stretching.
preferred label: TopologicalDescriptor

geometric descriptor
type: Class
subclass of: chemical descriptor
definition: A geometric descriptor is a descriptor that concerns information about size, shape, and relative position.
preferred label: GeometricDescriptor

ChargeDelocalizationDescriptor
type: Class
subclass of: ElectronicDescriptor
definition: Charge delocalization descriptor

hybridization descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: A hybridization descriptor is a chemical descriptor that is about the hybridization of atomic orbitals in a molecular entity.
preferred label: HybridizationDescriptor

atomic valence
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: Atomic valence is an atomic descriptor that specifies the maximum number of univalent atoms (originally hydrogen or chlorine atoms) which may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted [source: IUPAC Gold Book - http://goldbook.iupac.org/V06588.html]
preferred label: AtomicValence

atomic hardness descriptor
type: Class
subclass of: ChargeDelocalizationDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: An atomic hardness descriptor is an atomic descriptor that estimates the difference between the ionization potential and the electron affinity of a given atom.
preferred label: AtomicHardnessDescriptor

atomic softness descriptor
type: Class
subclass of: ChargeDelocalizationDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: An atomic softness descriptor is an atomic descriptor which is about the charge delocalizing ability of a given atom.
preferred label: AtomicSoftnessDescriptor

molecular QSAR descriptor
type: Class
subclass of: QSAR descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A molecular QSAR descriptor is a OSAR descriptor which gives a quantitative value to some aspect of a molecular entity.
preferred label: MolecularQSARDescriptor

cycle basis
type: Class
subclass of: structural descriptor
definition: The cycle basis of a molecular structure is the smallest set of cycles (closed paths) formed in the graph representation of the structure, from which all other cycles can be computed.
preferred label: CycleBasis

systematic name
type: Class
subclass of: molecular entity name
definition: A systematic name is a molecular entity name which is formulated systematically from the structure of the molecular entity.
preferred label: SystematicName

IUPAC name
type: Class
subclass of: systematic name
definition: An IUPAC name is a systematic name which is formulated according to the rules and recommendations for chemical nomenclature set out by the International Union of Pure and Applied Chemistry (IUPAC).
preferred label: IUPACName

trivial name
type: Class
subclass of: molecular entity name
definition: A trivial name is a molecular entity name that is in common public use and may not be related to the structure of the molecular entity.
preferred label: TrivialName

fused cycles
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: The fused cycles in a molecular structure are those cycles from the cycle basis which share at least one bond.
preferred label: FusedCycles

atomic QSAR descriptor
type: Class
subclass of: QSAR descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: An atomic QSAR descriptor is a QSAR descriptor which gives a quantitative value to some aspect of an atom which is part of a molecular entity.
preferred label: AtomicQSARDescriptor

InChI descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: An InChI descriptor is a structure descriptor which conforms to the InChI format specification.
preferred label: InChIDescriptor

MOLfile descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A MOLfile descriptor is a structure descriptor which conforms to the MOLfile format specification.
preferred label: MOLfileDescriptor

atomic connectivity index
type: Class
subclass of: geometric descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: An atomic connectivity index is an atomic descriptor that is a measure of atomic connectivity, which can take various forms (e.g. zero-order, or first-order).
preferred label: AtomicConnectivityIndex

Wiener path number
type: Class
subclass of: topological descriptor
definition: Half the sum of all the distance matrix entries, topological index of atom-atom distances.
preferred label: WienerPathNumber

formal charge descriptor
type: Class
subclass of: charge descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: The formal charge gives the charge assigned to an atom in a molecule, assuming that electrons in a chemical bond are shared equally between atoms, regardless of relative electronegativity. The formal charge of any atom in a molecule can be calculated by the following equation: FC = number of valence electrons of the atom in isolation (atom in ground state) - number of non-bonding electrons on this atom in the molecule - half the total number of electrons shared in covalent bonds with other atoms in the molecule. [source:wikipedia]
preferred label: FormalChargeDescriptor

partial charge descriptor
type: Class
subclass of: charge descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: A partial charge descriptor gives the charge with an absolute value of less than one elementary charge unit (that is, smaller than the charge of the electron). [source:wikipedia]
preferred label: PartialChargeDescriptor

electronegativity descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: An electronegativity descriptor is a chemical descriptor that is about the electronegativity quality of an atom.
preferred label: ElectronegativityDescriptor

chemical descriptor
type: Class
subclass of: Restriction
  on property: is about
  some values from: chemical entity
definition: A chemical descriptor is a data item (quantity or value) about a chemical entity that conforms to a specification for how it is calculated, measured or recorded.
preferred label: ChemicalDescriptor

bond multiplicity descriptor
type: Class
subclass of: ElectronicDescriptor
definition: A bond multiplicity descriptor is a chemical descriptor that in primitive cases is defined as half of the difference between the number of bonding and antibonding electrons in a particular system, but may also be defined with relation to the strength of a single bond.
preferred label: BondMultiplicityDescriptor

charge descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A charge descriptor is a chemical descriptor which indicates the charge of a chemical entity.
preferred label: ChargeDescriptor

bond length descriptor
type: Class
subclass of: dimensional extent descriptor
definition: A bond length descriptor is a dimensional extent descriptor which gives the measured or predicted (idealised) length of an atom to atom bond within a chemical entity.
preferred label: BondLengthDescriptor

ConstitutionalDescriptor
type: Class
subclass of: chemical descriptor
definition: Constitutional descriptor

Wiener polarity number descriptor
type: Class
subclass of: topological descriptor
definition: Half the sum of all the distance matrix entries with a value of 3
preferred label: WienerPolarityNumberDescriptor

PubChemCompoundIdentifier(CID)
type: Class
subclass of: PubChemIdentifier
definition: PubChem compound identifier (CID)

PubChemSubstanceIdentifier(SID)
type: Class
subclass of: PubChemIdentifier
definition: PubChem substance identifier (SID)

TopologicalSurfaceAreaDescriptor
type: Class
subclass of: surface area descriptor
definition: Topological surface area descriptor

generic SMILES descriptor
type: Class
subclass of: SMILES descriptor
definition: a generic SMILES descriptor is a SMILES descriptor that denotes only the labeled molecular graph (i.e. atoms and bonds, but no chiral or isotopic information).
preferred label: GenericSMILESDescriptor

TopologicalPolarSurfaceAreaDescriptor
type: Class
subclass of: TopologicalSurfaceAreaDescriptor
definition: Topological polar surface area descriptor

charge weighted partial negative surface area
type: Class
subclass of: surface area descriptor
alternative label: PNSA-3
definition: charge weighted partial negative surface area
preferred label: ChargeWeightedPartialNegativeSurfaceArea

DPSA-1
type: Class
subclass of: surface area descriptor
definition: difference of PPSA-1 and PNSA-1
preferred label: DPSAMinus1

DPSA-2
type: Class
subclass of: surface area descriptor
definition: difference of FPSA-2 and PNSA-2
preferred label: DPSAMinus2

DPSA-3
type: Class
subclass of: surface area descriptor
definition: difference of PPSA-3 and PNSA-3
preferred label: DPSAMinus3

FPSA-1
type: Class
subclass of: surface area descriptor
definition: PPSA-1 / total molecular surface area
preferred label: FPSAMinus1

FPSA-2
type: Class
subclass of: surface area descriptor
definition: PPSA-2 / total molecular surface area
preferred label: FPSAMinus2

FPSA-3
type: Class
subclass of: surface area descriptor
definition: PPSA-3 / total molecular surface area
preferred label: FPSAMinus3

FNSA-1
type: Class
subclass of: surface area descriptor
definition: PNSA-1 / total molecular surface area
preferred label: FNSAMinus1

FNSA-2
type: Class
subclass of: surface area descriptor
definition: PNSA-2 / total molecular surface area
preferred label: FNSAMinus2

FNSA-3
type: Class
subclass of: surface area descriptor
definition: PNSA-3 / total molecular surface area
preferred label: FNSAMinus3

WPSA-1
type: Class
subclass of: surface area descriptor
definition: PPSA-1 * total molecular surface area / 1000
preferred label: WPSAMinus1

WPSA-2
type: Class
subclass of: surface area descriptor
definition: PPSA-2 * total molecular surface area /1000
preferred label: WPSAMinus2

WPSA-3
type: Class
subclass of: surface area descriptor
definition: PPSA-3 * total molecular surface area /1000
preferred label: WPSAMinus3

WNSA-1
type: Class
subclass of: surface area descriptor
definition: PNSA-1 * total molecular surface area /1000
preferred label: WNSAMinus1

WNSA-2
type: Class
subclass of: surface area descriptor
definition: PNSA-2 * total molecular surface area /1000
preferred label: WNSAMinus2

WNSA-3
type: Class
subclass of: surface area descriptor
definition: PNSA-3 * total molecular surface area /1000
preferred label: WNSAMinus3

relative positive charge
type: Class
subclass of: surface area descriptor
alternative label: RPCG
definition: most positive charge / total positive charge
preferred label: RelativePositiveCharge

relative negative charge
type: Class
subclass of: surface area descriptor
alternative label: RNCG
definition: most negative charge / total negative charge
preferred label: RelativeNegativeCharge

relative positive charge surface area
type: Class
subclass of: surface area descriptor
alternative label: RPCS
definition: most positive surface area * RPCG
preferred label: RelativePositiveChargeSurfaceArea

relative negative charge surface area
type: Class
subclass of: surface area descriptor
alternative label: RNCS
definition: most negative surface area * RNCG
preferred label: RelativeNegativeChargeSurfaceArea

THSA
type: Class
subclass of: surface area descriptor
definition: sum of solvent accessible surface areas of atoms with absolute value of partial charges less than 0.2

TPSA
type: Class
subclass of: surface area descriptor
definition: sum of solvent accessible surface areas of atoms with absolute value of partial charges greater than or equal 0.2

RHSA
type: Class
subclass of: surface area descriptor
definition: THSA / total molecular surface area

RPSA
type: Class
subclass of: surface area descriptor
definition: TPSA / total molecular surface area

CollectionOf3DCoordinates
type: Class
subclass of: structural descriptor
definition: Collection of 3D coordinates

CollectionOf3DAtomicCoordinates
type: Class
subclass of: CollectionOf3DCoordinates
definition: Collection of 3D atomic coordinates

molecular polarizability
type: Class
subclass of: ChargeDelocalizationDescriptor
alternative label: BPol
definition: Sum of the absolute value of the difference between atomic polarizabilities of all bonded atoms in the molecule (including implicit hydrogens)
preferred label: MolecularPolarizability

fragment complexity descriptor
type: Class
subclass of: complexity descriptor
alternative label: FragmentComplexity
definition: defined as @cdk.cite{Nilakantan06}
preferred label: FragmentComplexityDescriptor

VertexAdjacencyMatrixDescriptor
type: Class
subclass of: geometric descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: Vertex adjacency matrix descriptor

Petitjean Topological Shape Index
type: Class
subclass of: Petitjean Shape Index
definition: A measure of the anisotropy in a molecule (as per Petitjean et al)
preferred label: PetitjeanTopologicalShapeIndex

Petitjean Geometric Shape Index
type: Class
subclass of: Petitjean Shape Index
definition: A measure of the anisotropy in a molecule (as per Bath et al)
preferred label: PetitjeanGeometricShapeIndex

Petitjean number
type: Class
subclass of: topological descriptor
alternative label: petitjeanNumber
definition: the eccentricity of a vertex corresponds to the distance from that vertex to the most remote vertex in the graph. The distance is obtained from the distance matrix as the count of edges between the two vertices. If r i is the largest matrix entry in row i of the distance matrix D, then the radius is defined as the smallest of the r i . The graph diameter D is defined as the largest vertex eccentricity in the graph. Petitjean Number is the value of ( diameter - radius ) diameter .
preferred label: PetitjeanNumber

Petitjean Shape Index
type: Class
subclass of: topological descriptor
alternative label: petitjeanShapeIndex
definition: A measure of the anisotropy in a molecule
preferred label: PetitjeanShapeIndex

XLogP descriptor
type: Class
subclass of: logP descriptor
alternative label: XLogP
definition: A LogP descriptor based on the atom-type method described in Wang, R., Fu, Y., and Lai, L.. A New Atom-Additive Method for Calculating Partition Coefficients, Journal of Chemical Information and Computer Sciences. vol. 37. 1997, pp. 615-621.
preferred label: XLogPDescriptor

MLogP descriptor
type: Class
subclass of: logP descriptor
alternative label: MannholdLogP
definition: A LogP descriptor based on a simple equation using the number of carbons and hetero atoms.
preferred label: MLogPDescriptor

MaximalRatioOfLengthToBreadthDescriptor
type: Class
subclass of: RatioOfLengthToBreadthDescriptor
definition: Maximal ratio of length to breadth descriptor

RatioOfLengthToBreadthDescriptor
type: Class
subclass of: geometric descriptor
IAO_0000115: A descriptor characterizing the ratio of the length to the breadth of a given entity.
definition: Ratio of length to breadth descriptor

MinimalRatioOfLengthToBreadthDescriptor
type: Class
subclass of: RatioOfLengthToBreadthDescriptor
definition: Minimal ratio of length to breadth descriptor

IonizationEnergyDescriptor
type: Class
subclass of: ChargeDelocalizationDescriptor
IAO_0000115: An ionization energy descriptor is a descriptor that describes the minimum amount of energy required to remove an electron (to an infinite distance) from an atom or molecule in a gaseous state. X + energy → X+ + e- The term 'ionization potential' has historically been used but is now no longer recommended.
IAO_0000118: ionization energy
IAO_0000118: ionization enthalpy
IAO_0000118: ionization potential
definition: Ionization energy descriptor

EccentricConnectivityIndexDescriptor
type: Class
subclass of: topological descriptor
alternative label: EccentricConnectivityIndex
definition: Eccentric connectivity index descriptor

EquilibriumConstant
type: Class
subclass of: ElectronicDescriptor
definition: Equilibrium constant

acid dissociation constant
type: Class
subclass of: EquilibriumConstant
alternative label: Ka
definition: the acid dissociation constant, Ka, is quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid-base reactions.
preferred label: AcidDissociationConstant

pKa
type: Class
subclass of: EquilibriumConstant
definition: the logarithmic measure of the acid dissociation constant (Ka)
preferred label: PKa

MolecularWeightCalculatedByPipelinePilot
type: Class
subclass of: average molecular weight descriptor
IAO_0000115: A molecular weight descriptor calculated by a relevant module of the Pipeline Pilot software tool.
definition: Molecular weight calculated by pipeline pilot

absolute SMILES descriptor
type: Class
subclass of: isomeric SMILES descriptor
definition: An absolute SMILES descriptor is an isomeric SMILES descriptor that is produced using a canonicalization algorithm.
preferred label: AbsoluteSMILESDescriptor

tautomer count
type: Class
subclass of: count descriptor
definition: a count descriptor that denotes the number of tautomers.
preferred label: TautomerCount

StereocenterCount
type: Class
subclass of: count descriptor
definition: Stereocenter count

AtomStereocenterCount
type: Class
subclass of: StereocenterCount
disjoint with: BondStereocenterCount
definition: Atom stereocenter count

DefinedAtomStereocenterCount
type: Class
subclass of: AtomStereocenterCount
definition: Defined atom stereocenter count

formation energy descriptor
type: Class
subclass of: energetic descriptor
definition: A formation energy descriptor is an energetic descriptor which gives the value for the energy of formation of a chemical entity.
preferred label: FormationEnergyDescriptor

solvation energy descriptor
type: Class
subclass of: energetic descriptor
definition: A solvation energy descriptor is a chemical descriptor which gives the value for the energy of dissolving a particular chemical entity in a solvent.
preferred label: SolvationEnergyDescriptor

count descriptor
type: Class
subclass of: ConstitutionalDescriptor
definition: A count descriptor is a chemical descriptor which is calculated by counting the number of features of a certain kind which are present in the chemical entity.
preferred label: CountDescriptor

dissociation energy descriptor
type: Class
subclass of: energetic descriptor
definition: A dissociation energy descriptor is an energetic descriptor which gives a value for the dissociation energy for a chemical entity.
preferred label: DissociationEnergyDescriptor

UndefinedAtomStereocenterCount
type: Class
subclass of: AtomStereocenterCount
definition: Undefined atom stereocenter count

BondStereocenterCount
type: Class
subclass of: StereocenterCount
definition: Bond stereocenter count

DefinedBondStereocenterCount
type: Class
subclass of: BondStereocenterCount
definition: Defined bond stereocenter count

UndefinedBondStereocenterCount
type: Class
subclass of: BondStereocenterCount
definition: Undefined bond stereocenter count

average molecular weight descriptor
type: Class
subclass of: MolecularMassDescriptor
definition: The mass of a molecule calculated using the average mass of each element weighted for its natural isotopic abundance. E.g., Carbon has two natural isotopes 12 and 13 with relative abundances of 98.9% and 1.1% to yield an average mass of 12.011 g/mol
preferred label: AverageMolecularWeightDescriptor

exact mass descriptor
type: Class
subclass of: MolecularMassDescriptor
definition: an exact mass descriptor corresponds to the mass of the most intense molecule/ion peak in an MS spec, and when calculated denotes the mass of an ion or a molecule containing most likely isotopic composition for a single random molecule.
preferred label: ExactMassDescriptor

monoisotopic mass descriptor
type: Class
subclass of: MolecularMassDescriptor
definition: The mass of a molecule calculated using the mass of the most abundant isotope of each element. E.g., Carbon has a monoisotopic mass of 12.000 g/mol.
preferred label: MonoisotopicMassDescriptor

complexity descriptor
type: Class
subclass of: structural descriptor
definition: A complexity descriptor denotes the how complicated a structure is, seen from both the point of view of the elements contained and its structural features .
preferred label: ComplexityDescriptor

pi-system size
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
alternative label: LargestPiSystem
definition: The integer number of atoms in a pi-orbital system.
preferred label: PiMinussystemSize

bond dissociation Gibbs energy descriptor
type: Class
subclass of: dissociation energy descriptor
definition: Bond dissociation Gibbs energy descriptor captures the Gibbs energy associated with the process of breaking the bond in question. This could be measured or calculated in vacuo or in a specific Solvent, at a given temperature and pressure. Depends on molecular conformation.
preferred label: BondDissociationGibbsEnergyDescriptor

solvation Gibbs energy descriptor
type: Class
subclass of: solvation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: The molecular entity solvation Gibbs energy descriptor reflects the Gibbs energy associated with the solvation of the molecular entity in question. This could be measured or calculated in vacuo or in a specific solvent, at a particular temperature and pressure. Depends on molecular conformation when computed.
preferred label: SolvationGibbsEnergyDescriptor

BondChargeDensityDescriptor
type: Class
subclass of: charge density descriptor
definition: Bond charge density descriptor

surface area descriptor
type: Class
subclass of: dimensional extent descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A surface area descriptor is a descriptor which describes a measure or calculation of the surface area of a chemical entity.
preferred label: SurfaceAreaDescriptor

charge density descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A charge density descriptor is a chemical entity descriptor which indicates the distribution of the electric charge over the volume of the chemical entity.
preferred label: ChargeDensityDescriptor

aromatic atom count
type: Class
subclass of: atom count
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that provides the integer count of aromatic atoms in a given molecular entity.
preferred label: AromaticAtomCount

bond count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that specifies the integer count of bonds in a given molecular entity.
preferred label: BondCount

PubChemConformerIdentifier
type: Class
subclass of: PubChemCompoundIdentifier(CID)
definition: PubChem conformer identifier

bond aromaticity descriptor
type: Class
subclass of: aromaticity descriptor
subclass of: Restriction
  on property: has value
  some values from: boolean
definition: A bond aromaticity descriptor is an aromaticity descriptor associated with a bond within a chemical entity which indicates whether that bond belongs to an aromatic system.
preferred label: BondAromaticityDescriptor

formation Gibbs energy descriptor
type: Class
subclass of: formation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: The formation Gibbs energy descriptor captures the Gibbs energy associated with the formation of a molecular entity, relative to the standard state of constituent atoms. This can be measured, calculated in vacuo, or calculated with respect to a specific solvent, at a particular temperature and pressure. When calculated, the formation Gibbs energy value depends on the molecular conformation.
preferred label: FormationGibbsEnergyDescriptor

size of largest aliphatic chain
type: Class
subclass of: size of largest chain
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: The largest aliphatic chain size descriptor is a count descriptor that gives the integer length (number of atoms) in the largest unbranched chain of atoms that does not contain aromatic atoms, within a given molecular entity.
preferred label: SizeOfLargestAliphaticChain

formation enthalpy descriptor
type: Class
subclass of: formation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
IAO_0000118: enthalpy of formation
IAO_0000118: heat of formation
definition: Molecular entity formation enthaply descriptor captures the enthalpy associated with the formation of the molecular entity in question, relative to the standard state of constituent atoms. This could be measured or calculated in vacuo or in a specific Solvent, at a particular temperature and pressure. Depends on molecular conformation when computed.
preferred label: FormationEnthalpyDescriptor

volume descriptor
type: Class
subclass of: dimensional extent descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A volume descriptor is a descriptor which describes a measure or calculation of the volume of a chemical entity.
preferred label: VolumeDescriptor

aromatic bond count
type: Class
subclass of: bond count
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that provides the integer count of aromatic bonds in a given molecular entity.
preferred label: AromaticBondCount

hydrogen bond donor count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that reflects the integer number of hydrogen bond donors in a given molecular entity, as determined by a given method. In highly simplified terms, this is usually the count of all negatively or partially negatively charged heteroatoms (e.g. alcohol oxygen) that have covalently attached to them partially positively charged hydrogen atoms that are capable of participating in a hydrogen bond.
preferred label: HydrogenBondDonorCount

hydrogen bond acceptor count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that reflects the integer number of hydrogen bond acceptors in a given molecular entity, as determined by a given method. In highly simplified terms, this is usually the count of all negatively or partially negatively charged heteroatoms (e.g. alcohol oxygen) capable of accepting a hydrogen bond.
preferred label: HydrogenBondAcceptorCount

size of largest chain
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: The largest chain size descriptor is a count descriptor that gives the integer length (number of atoms) in the largest chain in a molecular entity.
preferred label: SizeOfLargestChain

solvation entropy descriptor
type: Class
subclass of: solvation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: The molecular entity solvation entropy descriptor reflects the entropy associated with the solvation of the molecular entity in question. This could be measured or calculated in vacuo or in a specific solvent, at a particular temperature and pressure. Depends on molecular conformation when computed.
preferred label: SolvationEntropyDescriptor

solvation enthalpy descriptor
type: Class
subclass of: solvation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: The molecular entity solvation enthalpy descriptor reflects the enthalpy associated with the solvation of the molecular entity in question. This could be measured or calculated in vacuo or in a specific solvent, at a particular temperature and pressure. Depends on molecular conformation when computed.
preferred label: SolvationEnthalpyDescriptor

logP descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: The logarithm of octanol-water partition coefficient, which is the ratio of the molecules dissolved in octanol to those dissolved in pure un-ionized water upon mixture equilibration. This can be measured or predicted. The value is dimensionless. May depend on molecular conformation when computed.
preferred label: LogPDescriptor

bond dissociation enthalpy descriptor
type: Class
subclass of: dissociation energy descriptor
definition: Bond dissociation enthalpy descriptor captures the enthalpy associated with the process of breaking the bond in question. This could be measured or calculated in vacuo or in a specific Solvent, at a given temperature and pressure. Depends on molecular conformation.
preferred label: BondDissociationEnthalpyDescriptor

refractive index descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: Chemical substance refractive index descriptor is a unitless descriptor that specifies the ratio of the speed of light in vacuum to that in a given chemical substance. [IUPAC: http://goldbook.iupac.org/R05240.html]
preferred label: RefractiveIndexDescriptor

rotatable bond count
type: Class
subclass of: bond count
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
alternative label: RotatableBondsCount
definition: a bond count that denotes the integer number of rotors in the molecule, generally single bonds torsion around which produces non-identical geometric molecular configurations.
preferred label: RotatableBondCount

MeltingPointDescriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: Melting point descriptor
definition: Melting point descriptor specifies the temperature at which a chemical substance undergoes the transition from solid to liquid state under standard conditions.

BoilingPointDescriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: Boiling point descriptor
definition: The boiling point descriptor indicates the temperature at which a chemical substance undergoes a state transition from liquid to gas, at standard conditions.

formation entropy descriptor
type: Class
subclass of: formation energy descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: Molecular entity formaiton entropy descriptor captures the entropy associated with the formation of the molecular entity in question, relative to the standard state of constituent atoms. This could be measured or calculated in vacuo or in a specific Solvent, at a particular temperature and pressure. Depends on molecular conformation when computed.
preferred label: FormationEntropyDescriptor

relative permittivity descriptor
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: The relative permittivity descriptor specifies the ratio of the electric field strength in vacuum to that in a given medium. It was formerly called the dielectric constant. [IUPAC Gold Book: http://goldbook.iupac.org/R05273.html ]
preferred label: RelativePermittivityDescriptor

atom count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that specifies the integer count of atoms in a given molecular entity.
preferred label: AtomCount

AtomicChargeDensityDescriptor
type: Class
subclass of: charge density descriptor
subclass of: Restriction
  on property: is about
  some values from: atom
definition: Atomic charge density descriptor

bond dissociation entropy descriptor
type: Class
subclass of: dissociation energy descriptor
definition: Bond dissociation entropy descriptor captures the entropy associated with the process of breaking the bond in question. This could be measured or calculated in vacuo or in a specific Solvent, at a given temperature and pressure. Depends on molecular conformation.
preferred label: BondDissociationEntropyDescriptor

ChemicalSubstance
type: Class
subclass of: chemical entity
definition: Chemical substance
definition: Chemical substance constitutes matter of constant composition, that may contain a collection of molecular entities. [IUPAC: http://goldbook.iupac.org/C01039.html]

effective rotor count
type: Class
subclass of: count descriptor
definition: A count descriptor that takes into account flexibility of rings and rotatable bonds.
preferred label: EffectiveRotorCount

total formal charge descriptor
type: Class
subclass of: charge descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: A charge descriptor that gives the total charge for a molecule
preferred label: TotalFormalChargeDescriptor

ConformerVolumeDescriptor
type: Class
subclass of: volume descriptor
definition: Conformer volume descriptor

amino acid count
type: Class
subclass of: count descriptor
definition: a count of the number of amino acid residues.
preferred label: AminoAcidCount

AlanineCount
type: Class
subclass of: amino acid count
definition: Alanine count

ArginineCount
type: Class
subclass of: amino acid count
definition: Arginine count

AsparagineCount
type: Class
subclass of: amino acid count
definition: Asparagine count

AspartateCount
type: Class
subclass of: amino acid count
definition: Aspartate count

CysteineCount
type: Class
subclass of: amino acid count
definition: Cysteine count

PhenylalanineCount
type: Class
subclass of: amino acid count
definition: Phenylalanine count

GlutamateCount
type: Class
subclass of: amino acid count
definition: Glutamate count

GlutamineCount
type: Class
subclass of: amino acid count
definition: Glutamine count

GlycineCount
type: Class
subclass of: amino acid count
definition: Glycine count

covalent unit count
type: Class
subclass of: count descriptor
subclass of: amino acid count
label: histidine count
definition: The number of covalent units (molecule / ion) in a chemical structure
preferred label: CovalentUnitCount
preferred label: HistidineCount

IsoleucineCount
type: Class
subclass of: amino acid count
definition: Isoleucine count

ProlineCount
type: Class
subclass of: amino acid count
definition: Proline count

LeucineCount
type: Class
subclass of: amino acid count
definition: Leucine count

LysineCount
type: Class
subclass of: amino acid count
definition: Lysine count

MethionineCount
type: Class
subclass of: amino acid count
definition: Methionine count

SerineCount
type: Class
subclass of: amino acid count
definition: Serine count

ThreonineCount
type: Class
subclass of: amino acid count
definition: Threonine count

TyrosineCount
type: Class
subclass of: amino acid count
definition: Tyrosine count

ValineCount
type: Class
subclass of: amino acid count
definition: Valine count

TryptophanCount
type: Class
subclass of: amino acid count
definition: Tryptophan count

Highest Occupied Molecular Orbital Energy
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: chemical entity
definition: A descriptor that the energy of the highest occupied 'molecular' orbital of the chemical entity.
preferred label: HighestOccupiedMolecularOrbitalEnergy

Lowest Unoccupied Molecular Orbital Energy
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: chemical entity
definition: A descriptor that the energy of the lowest unoccupied 'molecular' orbital of the chemical entity.
preferred label: LowestUnoccupiedMolecularOrbitalEnergy

acidic group count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that specifies the integer count of acidic groups in a given molecular entity.
preferred label: AcidicGroupCount

basic group count
type: Class
subclass of: count descriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
subclass of: Restriction
  on property: has value
  some values from: int
definition: A descriptor that specifies the integer count of basic groups in a given molecular entity.
preferred label: BasicGroupCount

ALogP descriptor
type: Class
subclass of: logP descriptor
alternative label: ALogP
definition: The ALogP descriptor described by Ghose and Crippen in 1986 and 1987.
preferred label: ALogPDescriptor

HybridizationDescriptor(VSEPR)
type: Class
subclass of: hybridization descriptor
definition: Hybridization descriptor (VSEPR)

InductiveAtomicHardness
type: Class
subclass of: ElectronicDescriptor
definition: Inductive atomic hardness

TPSA(fragments)
type: Class
subclass of: TopologicalPolarSurfaceAreaDescriptor
definition: TPSA (fragments)

VABCVolumeDescriptor
type: Class
subclass of: volume descriptor
definition: VABC volume descriptor

heavy atom count
type: Class
subclass of: atom count
definition: The number of non-hydrogen atoms
preferred label: HeavyAtomCount

isotope atom count
type: Class
subclass of: atom count
definition: The sum of all atoms enriched with respect to a particular atom isotope
preferred label: IsotopeAtomCount

PubChemIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: PubChem Identifier

GenBankProteinIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: GenBank Protein Identifier

GenBankNucleotideIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: GenBank Nucleotide Identifier

ALogPCalculatedByPipelinePilot
type: Class
subclass of: ALogP descriptor
definition: ALogP calculated by Pipeline Pilot

PolarSurfaceAreaDescriptor
type: Class
subclass of: surface area descriptor
definition: Polar surface area descriptor

PolarSurfaceAreaDescriptorCalculatedByPipelinePilot
type: Class
subclass of: PolarSurfaceAreaDescriptor
definition: Polar surface area descriptor calculated by Pipeline Pilot

HydrogenBondAcceptorCountCalculatedByPipelinePilot
type: Class
subclass of: hydrogen bond acceptor count
definition: Hydrogen bond acceptor count calculated by pipeline pilot

HydrogenBondDonorCountCalculatedByPipelinePilot
type: Class
subclass of: hydrogen bond donor count
definition: Hydrogen bond donor count calculated by pipeline pilot

RotatableBondCountCalculatedByPipelinePilot
type: Class
subclass of: rotatable bond count
definition: Rotatable bond count calculated by pipeline pilot

RuleOfFiveViolationsDescriptor
type: Class
subclass of: physical descriptor
IAO_0000115: Number of properties defined in Lipinski’s Rule of 5 (RO5) that the compound fails. Conditions which violate the RO5 are: Molecular weight>=500 AlogP>=5 HBD>=5 HBA>=10
definition: Rule of five violations descriptor

RuleOfFiveViolationsCalculatedByPipelinePilot
type: Class
subclass of: RuleOfFiveViolationsDescriptor
definition: Rule of five violations calculated by pipeline pilot

RuleOfThreePassesDescriptor
type: Class
subclass of: physical descriptor
IAO_0000115: Rule of 3 passes. It is suggested that compounds that pass all these criteria are more likely to be hits in fragment screening. molecular weight <=300, number of hydrogen bond donors <=3, number of hydrogen bond acceptors <=3 AlogP <=3. RTB <=3 PSA<=60
definition: Rule of three passes descriptor

RuleOfThreePassesCalculatedByPipelinePilot
type: Class
subclass of: RuleOfThreePassesDescriptor
definition: Rule of three passes calculated by pipeline pilot

MedchemFriendlyDescriptor
type: Class
subclass of: physical descriptor
IAO_0000115: MedChem Friendly These are functional groups that may not be desirable from a medicinal chemistry perspective. For example reactive groups will be flagged as “N” (not MedChem Friendly). Molecules which do not contain any of these groups will be flagged as “Y” (MedChem Friendly). The groups are defined by the following list of SMARTS: [N+]([O-])=O [C;!R](-[C;!R]=O)=[C;!R] C(-N)=S P O-N=C OS(=O)=O O1-CC-O-C-1 C(-N)=C [C;H2]-[C;H2]-[C;H2]-[C;H2]-[C;H2]-[C;H2]-[C;H2] OC1OCC(O)C1 C=N-C(-O) [N;H]-[C;H]-[N;H] [C;!R]=[C;!R]-N-[C;D1&H3,D2&H2,D3&H1,D4] [S;!R]-[C;!R]-[O;!R] [O;D2]-[C;!H0](([F,Br,I,Cl])([F,Br,I,Cl])([!F,!Br,!I,!Cl])) CC([O;!R])([O;!R]) C1-C-O1 C(=O)-S-C(=S) [S;H] SC#N
definition: Medchem friendly descriptor

MedchemFriendlyDescriptorCalculatedByPipelinePilot
type: Class
subclass of: MedchemFriendlyDescriptor
definition: Medchem friendly descriptor calculated by pipeline pilot

LogPCalculatedByACDLabsPhysChemSoftware
type: Class
subclass of: logP descriptor
definition: LogP calculated by ACD/Labs PhysChem software

LogDDescriptor
type: Class
subclass of: physical descriptor
IAO_0000115: octanol-water distribution coefficient calculated at a given pH.
definition: LogD descriptor

CHEMINF_000323
type: Class
subclass of: LogDDescriptor
IAO_0000115: ACD_LogD(pH7.4) Distribution Coefficient calculated at pH7.4
definition: LogD calculated at pH 7.4 by ACD/Labs PhysChem software

MostAcidicPKaCalculatedByACDLabsPhysChemSoftwareLibrary
type: Class
subclass of: pKa
IAO_0000115: Most acidic pKa of the molecule
definition: Most acidic pKa calculated by ACD/Labs PhysChem software library

MostBasicPKaCalculatedByACDLabsPhysChemSoftwareLibrary
type: Class
subclass of: pKa
IAO_0000115: Most basic pKa of the molecule
definition: Most basic pKa calculated by ACD/Labs PhysChem software library

MolecularSpeciesAtPH7.4Descriptor
type: Class
subclass of: physical descriptor
IAO_0000115: Molecular Species is a description of the predominant form of the molecule at pH7.4.
definition: Molecular species at pH 7.4 descriptor

CHEMINF_000327
type: Class
subclass of: MolecularSpeciesAtPH7.4Descriptor
IAO_0000115: These are defined according to the definitions: Acid(A) ACD_MOST_ApKa <6.5 and ACD_MOST_BpKa<8.5 Bas (B) ACD_MOST_ApKa >6.5 and ACD_MOST_BpKa>8.5 Neutral (N) ACD_MOST_ApKa >6.5 and ACD_MOST_BpKa<8.5 Zwitterion (ZW) ACD_MOST_ApKa <6.5 and ACD_MOST_BpKa>8.5
definition: Molecular species at pH 7.4 calculated by ACD/Labs PhysChem software

MolecularWeightCalculatedByThePubchemSoftwareLibrary
type: Class
subclass of: average molecular weight descriptor
definition: Molecular weight calculated by the pubchem software library

MolecularFormulaCalculatedByThePubchemSoftwareLibrary
type: Class
subclass of: molecular formula
definition: Molecular formula calculated by the pubchem software library

TotalFormalChargeCalculatedByThePubchemSoftwareLibrary
type: Class
subclass of: total formal charge descriptor
definition: Total formal charge calculated by the pubchem software library

MonoisotopicMassCalculatedByThePubchemSoftwareLibrary
type: Class
subclass of: monoisotopic mass descriptor
definition: Monoisotopic mass calculated by the pubchem software library

ExactMassCalculatedByPubchemSoftwareLibrary
type: Class
subclass of: exact mass descriptor
definition: Exact mass calculated by pubchem software library

PubchemDepositorMinussuppliedMolecularEntityName
type: Class
subclass of: molecular entity name
IAO_0000115: A molecular entity name that has been supplied by a depositor to the PubChem database. This is just a molecular entity name with additional provenance associated.
definition: Pubchem depositor-supplied molecular entity name

logD calculated at pH 5.5 by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: LogDDescriptor
definition: Octanol-water distribution coefficient calculated at pH 5.5 by ACD/Labs PhysChem software library version 12.01.

hydrogen bond acceptor count calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: hydrogen bond acceptor count
definition: Hydrogen bond acceptor count that has been calculated by ACD/Labs PhysChem software library version 12.01.

hydrogen bond donor count calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: hydrogen bond donor count
definition: Hydrogen bond donor count that has been calculated by ACD/Labs PhysChem software library version 12.01.

Boiling point at 760 mmHg pressure calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: BoilingPointDescriptor
definition: The boiling point of a substance at 760 mmHg pressure that has been calculated by ACD/Labs PhysChem software library version 12.01.

number of freely rotating bonds calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: rotatable bond count
definition: Number of freely rotating bonds that has been calculated by ACD/Labs PhysChem software library version 12.01.

polar surface area calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: PolarSurfaceAreaDescriptor
definition: Polar surface area that has been calculated by ACD/Labs PhysChem software library version 12.01.

molecular weight of the corresponding free base
type: Class
subclass of: average molecular weight descriptor
definition: The molecular weight for the free base chemical structure matching this chemical structure.
preferred label: MolecularWeightOfTheCorrespondingFreeBase

molar refractivity calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: molar refractivity
definition: Molar refractivity that has been calculated by ACD/Labs PhysChem software library version 12.01.

index of refraction calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: refractive index descriptor
definition: Index of refraction that has been calculated by ACD/Labs PhysChem software library version 12.01.

molar volume calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: molar volume descriptor
definition: Molar volume that has been calculated by ACD/Labs PhysChem software library version 12.01.

density calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: density descriptor
definition: Density that has been calculated by ACD/Labs PhysChem software library version 12.01.

flash point calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: flash point descriptor
definition: Flash point that has been calculated by ACD/Labs PhysChem software library version 12.01.

enthalpy of vaporization calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: enthalpy of vaporization descriptor
definition: Enthalpy of vaporization that has been calculated by ACD/Labs PhysChem software library version 12.01.

vapour pressure calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: vapour pressure descriptor
definition: Vapour pressure that has been calculated by ACD/Labs PhysChem software library version 12.01.

organic carbon adsorption coefficient at pH 5.5 calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: organic carbon adsorption descriptor
definition: Organic carbon adsorption coefficient at pH 5.5 that has been calculated by ACD/Labs PhysChem software library version 12.01.

organic carbon adsorption coefficient at pH 7.4 calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: organic carbon adsorption descriptor
definition: Organic carbon adsorption coefficient at pH 7.4 that has been calculated by ACD/Labs PhysChem software library version 12.01.

bioconcentration factor at pH 5.5 calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: bioconcentration factor descriptor
definition: Bioconcentration factor at pH 7.4 that has been calculated by ACD/Labs PhysChem software library version 12.01.

bioconcentration factor at pH 7.4 calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: bioconcentration factor descriptor
definition: Bioconcentration factor at pH 7.4 that has been calculated by ACD/Labs PhysChem software library version 12.01.

number of rule of five violations calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: RuleOfFiveViolationsDescriptor
definition: Number of rule of five violations for a chemical structure that has been calculated by ACD/Labs PhysChem software library version 12.01.

surface tension calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: surface tension descriptor
definition: Surface tension, in dyne per centimetre, that has been calculated by ACD/Labs PhysChem software library version 12.01.

CovalentUnitCountGeneratedByPubchemSoftwareLibrary
type: Class
subclass of: covalent unit count
definition: Covalent unit count generated by pubchem software library

DefinedAtomStereocenterCountGeneratedByThePubchemSoftwareLibrary
type: Class
subclass of: DefinedAtomStereocenterCount
definition: Defined atom stereocenter count generated by the pubchem software library

DefinedBondStereocenterCountGeneratedByPubchemSoftwareLibrary
type: Class
subclass of: DefinedBondStereocenterCount
definition: Defined bond stereocenter count generated by pubchem software library

IsotopeAtomCountGeneratedByPubchemSoftwareLibrary
type: Class
subclass of: isotope atom count
definition: Isotope atom count generated by pubchem software library

HeavyAtomCountGeneratedByPubchemSoftwareLibrary
type: Class
subclass of: heavy atom count
definition: Heavy atom count generated by pubchem software library

UndefinedAtomStereocenterCountGeneratedByThePubchemSoftwareLibrary
type: Class
subclass of: UndefinedAtomStereocenterCount
definition: Undefined atom stereocenter count generated by the pubchem software library

UndefinedBondStereocenterCountGeneratedByThePubchemSoftwareLibrary
type: Class
subclass of: UndefinedBondStereocenterCount
definition: Undefined bond stereocenter count generated by the pubchem software library

CanonicalSmilesGeneratedByOEChem
type: Class
subclass of: canonical SMILES descriptor
definition: Canonical smiles generated by OEChem

IsomericSMILESGeneratedByOEChem
type: Class
subclass of: isomeric SMILES descriptor
definition: Isomeric SMILES generated by OEChem

CycleCount
type: Class
subclass of: count descriptor
IAO_0000115: A descriptor that specifies the integer count of cycles in a given molecular entity.
definition: Cycle count

AromaticCycleCount
type: Class
subclass of: CycleCount
IAO_0000115: A descriptor that specifies the integer count of aromatic cycles in a given molecular entity.
IAO_0000118: aromatic rings
definition: Aromatic cycle count

IUPACNameGeneratedByLexiChem
type: Class
subclass of: IUPAC name
definition: IUPAC Name generated by LexiChem

HydrogenBondDonorCountCalculatedByCactvs
type: Class
subclass of: hydrogen bond donor count
definition: Hydrogen bond donor count calculated by cactvs

HydrogenBondAcceptorCountCalculatedByCactvs
type: Class
subclass of: hydrogen bond acceptor count
definition: Hydrogen bond acceptor count calculated by cactvs

RotatableBondCountCalculatedByCactvs
type: Class
subclass of: rotatable bond count
definition: Rotatable bond count calculated by cactvs

StructureComplexityCalculatedByCactvs
type: Class
subclass of: complexity descriptor
definition: Structure complexity calculated by cactvs

TautomerCountCalculatedByCactvs
type: Class
subclass of: tautomer count
definition: Tautomer count calculated by cactvs

TPSACalculatedByCactvs
type: Class
subclass of: TPSA
definition: TPSA calculated by cactvs

Xlogp3CalculatedByTheXlogp3Software
type: Class
subclass of: XLogP descriptor
definition: Xlogp3 calculated by the xlogp3 software

InChICalculatedByLibraryVersion1.0.4
type: Class
subclass of: InChI descriptor
definition: InChI calculated by library version 1.0.4

InChIKeyGeneratedBySoftwareVersion1.0.4
type: Class
subclass of: InChIKey
definition: InChIKey generated by software version 1.0.4

chemical graph
type: Class
subclass of: structural descriptor
definition: A chemical graph is a structural descriptor in which the connectivity and constitution of the chemical entity are described in terms of a mathematical graph, usually with atoms as vertices and bonds as edges, but other variants exist.
preferred label: ChemicalGraph

ChemSpider identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by ChemSpider.
preferred label: ChemSpiderIdentifier

DrugBank identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by DrugBank.
preferred label: DrugBankIdentifier

ChEBI identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by ChEBI.
preferred label: ChEBIIdentifier

HMDB identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by Human Metabolome Database.
preferred label: HMDBIdentifier

KEGG identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by KEGG.
preferred label: KEGGIdentifier

Reactome identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Database identifier used by Reactome.
preferred label: ReactomeIdentifier

ChEMBL identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Identifier used by the ChEMBL database for compounds, assays, target, etc.
preferred label: ChEMBLIdentifier

organic carbon adsorption descriptor
type: Class
subclass of: physical descriptor
IAO_0000117: Colin Batchelor
definition: A descriptor of the ratio of the amount of a given chemical substance adsorbed per unit weight of organic carbon in soil or sediment to the concentration of the chemical substance in solution at equilibrium.
preferred label: OrganicCarbonAdsorptionDescriptor

bioconcentration factor descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
IAO_0000117: Colin Batchelor
definition: A descriptor of the ratio of the concentration of a chemical substance in an organism immersed in water to that in the surrounding water at equilibrium.
preferred label: BioconcentrationFactorDescriptor

molar volume descriptor
type: Class
subclass of: physical descriptor
IAO_0000117: Colin Batchelor
definition: A descriptor of the volume occupied by one mole of the given substance at a given temperature and pressure.
preferred label: MolarVolumeDescriptor

density descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
IAO_0000117: Colin Batchelor
definition: A descriptor of the density of a given substance at a given temperature and pressure.
preferred label: DensityDescriptor

flash point descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
IAO_0000117: Colin Batchelor
definition: A descriptor of the flash point of a substance at a given pressure. The flash point is the minimum temperature at which a mixture of the substance with air can be ignited, within its explosive range.
preferred label: FlashPointDescriptor

enthalpy of vaporization descriptor
type: Class
subclass of: physical descriptor
IAO_0000117: Colin Batchelor
definition: A descriptor of the energy taken in by a chemical substance on vaporization at a given temperature and pressure.
preferred label: EnthalpyOfVaporizationDescriptor

vapour pressure descriptor
type: Class
subclass of: physical descriptor
IAO_0000117: Colin Batchelor
definition: A descriptor of the pressure exerted by the vapour phase of a chemical substance on its condensed phase at a given temperature and pressure.
preferred label: VapourPressureDescriptor

surface tension descriptor
type: Class
subclass of: physical descriptor
IAO_0000117: Colin Batchelor
definition: A descriptor of the disposition of a portion of liquid to resist a force.
preferred label: SurfaceTensionDescriptor

StructuralAlertCount
type: Class
subclass of: count descriptor
IAO_0000115: The number of structural alerts, that is, unwanted features as defined according to the procedure followed in Brenk et al., 2008. Brenk R, et al. Lessons learnt from assembling screening libraries for drug discovery for neglected diseases. Chem Med Chem. 2008;3:435–444.
definition: Structural alert count

WeightedQuantitativeEstimateOfDrugMinuslikeness
type: Class
subclass of: physical descriptor
IAO_0000115: A descriptor which gives a quantitative estimate of drug likeness according to the procedure outlined in Bickerton et al., 2012. http://www.ncbi.nlm.nih.gov/pubmed/22270643 Nat Chem. 2012 Jan 24;4(2):90-8. doi: 10.1038/nchem.1243. Quantifying the chemical beauty of drugs. Bickerton GR, Paolini GV, Besnard J, Muresan S, Hopkins AL.
IAO_0000118: QED weighted
definition: Weighted quantitative estimate of drug-likeness

freezing point descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A descriptor that indicates the temperature at which a chemical substance undergoes a state transition from gas or liquid to solid, under standard conditions.
preferred label: FreezingPointDescriptor

Henry's Law constant
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: Henry's law, formulated by William Henry in 1803, states "At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid." Henry's law can be put into mathematical terms (at constant temperature) as p = kHc where p is the partial pressure of the solute in the gas above the solution, c is the concentration of the solute and kH is a constant with the dimensions of pressure divided by concentration. The constant, known as the Henry's law constant, depends on the solute, the solvent and the temperature.
preferred label: HenrysLawConstant

atmospheric OH rate constant
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the rate constant of a reaction of a chemical entity with OH. This is used to describe the atmospheric behaviour (i.e. stability) of the entity.
preferred label: AtmosphericOHRateConstant

upper explosive limit descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the upper explosive limit of the entity in air as a percentage by volume at room temperature.
preferred label: UpperExplosiveLimitDescriptor

lower explosive limit descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the lower explosive limit in air as a percentage by volume at room temperature
preferred label: LowerExplosiveLimitDescriptor

minimum explosive concentration descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the minimum explosive concentration.
preferred label: MinimumExplosiveConcentrationDescriptor

specific gravity descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor of the ratio of the density of chemical substance to the density of a reference substance. The reference substance is usually water for liquids or air for gases.
preferred label: SpecificGravityDescriptor

relative density descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A descriptor of the relative density of gases referenced to air as 1, which indicates how many times a gas is heavier than air at the same temperature.
preferred label: RelativeDensityDescriptor

vapor density descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A descriptor of the density of a vapour in relation in that of hydrogen, defined as the mass of a certain volume of the given substance divided by the mass of the same volume of hydrogen.
preferred label: VaporDensityDescriptor

odor detection threshold descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the lowest concentration of an odorant chemical entity that is perceivable by the human sense of smell.
preferred label: OdorDetectionThresholdDescriptor

pH descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor which gives a measure of the acidity or basicity of an aqueous solution, defined as the decimal logarithm of the reciprocal of the hydrogen ion activity in a solution.
preferred label: PHDescriptor

evaporation rate descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor of the rate of evaporation of a liquid under standard conditions.
preferred label: EvaporationRateDescriptor

autoignition temperature descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
IAO_0000118: kindling point
definition: A physical descriptor of the lowest temperature at a substance will spontaneously ignite in a normal atmosphere without an external source of ignition.
preferred label: AutoignitionTemperatureDescriptor

soil half-life descriptor
type: Class
subclass of: physical descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: A physical descriptor for the time it takes for half of a portion of substance of a given type to decompose in soil under standard conditions.
preferred label: SoilHalfMinuslifeDescriptor

CAS registry number
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Identifier used by the Chemical Abstracts Service database.
preferred label: CASRegistryNumber

EC number
type: Class
subclass of: ChemicalDatabaseIdentifier
label: EINECS No
label: European Community number
definition: A seven-digit identifier for chemical substances for regulatory purposes within the European Union.
preferred label: ECNumber
preferred label: EINECSNo
preferred label: EuropeanCommunityNumber

MetalAtomCount
type: Class
subclass of: atom count
IAO_0000115: A descriptor that specifies the integer count of metal atoms in a given chemical entity.
definition: Metal atom count

OxygenAtomCount
type: Class
subclass of: atom count
IAO_0000115: A descriptor that specifies the integer count of oxygen atoms in a given chemical entity.
definition: Oxygen atom count

ChemicalDatabaseIdentifier
type: Class
subclass of: identifying descriptor
IAO_0000115: An identifying descriptor which is used within a particular database system to identify a chemical system.
IAO_0000117: Person: Colin Batchelor
definition: Chemical database identifier

ChemSpiderValidatedSynonym
type: Class
subclass of: preferred name
IAO_0000115: A preferred name in ChemSpider by virtue of having been validated by a curator.
IAO_0000117: Person: Colin Batchelor
definition: ChemSpider validated synonym

ChemSpiderUnvalidatedSynonym
type: Class
subclass of: molecular entity name
IAO_0000115: A molecular entity name in the ChemSpider database which has not been validated by a curator.
IAO_0000117: Person: Colin Batchelor
definition: ChemSpider unvalidated synonym

ValidatedChemicalDatabaseIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
IAO_0000115: A chemical database identifier which has been validated by a curator.
IAO_0000117: Person: Colin Batchelor
definition: Validated chemical database identifier

ChemSpiderTitle
type: Class
subclass of: ChemSpiderValidatedSynonym
IAO_0000115: A ChemSpider validated synonym that has been identified as a title by the ChemSpider software.
definition: ChemSpider title

CHEMINF_000484
type: Class
subclass of: average molecular weight descriptor
IAO_0000117: Person: Colin Batchelor
definition: Average molecular weight descriptor calculated by ACD/Labs PhysChem software library version 12.01

CHEMINF_000485
type: Class
subclass of: monoisotopic mass descriptor
IAO_0000117: Person: Colin Batchelor
definition: Monoisotopic molecular weight descriptor calculated by ACD/Labs PhysChem software library version 12.01

EnergyBandGap
type: Class
subclass of: energetic descriptor
IAO_0000115: A descriptor that describes the energy range in a solid where no electron states can exist. In graphs of the electron band structure of solids, the band gap generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. [http://en.wikipedia.org/wiki/Band_gap]
IAO_0000118: band gap
IAO_0000118: energy gap
definition: Energy band gap

MetalElementMassDescriptor
type: Class
subclass of: MassDescriptor
IAO_0000115: A descriptor describing the mass of the metal element component of a composite substance.
IAO_0000118: metal element mass
definition: Metal element mass descriptor

molecular formula calculated by ACD/Labs PhysChem software library version 12.01
type: Class
subclass of: molecular formula
definition: Molecular formula for a chemical structure as calculated by ACD/Labs PhysChem software library version 12.01.

PartitionCoefficient
type: Class
subclass of: physical descriptor
IAO_0000115: The ratio of a dissolved substance in a two-phase system, giving a measure of the difference in solubility of the substance in the two phases.
definition: Partition coefficient

NumericChemicalDescriptor
type: Class
subclass of: chemical descriptor
definition: Numeric chemical descriptor

TextualChemicalDescriptor
type: Class
subclass of: chemical descriptor
definition: Textual chemical descriptor

ChemicalSubstanceDescriptor
type: Class
subclass of: chemical descriptor
definition: Chemical substance descriptor

group of an atom
type: Class
subclass of: ConstitutionalDescriptor
definition: Descriptor that returns the group in the periodic table of a given atom.
preferred label: GroupOfAnAtom

NInChI descriptor
type: Class
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: ChemicalSubstance
definition: An InChI-like descriptor for nanomaterials.
preferred label: NInChIDescriptor

TUCAN descriptor
type: Class
subclass of: identifying descriptor
subclass of: structural descriptor
subclass of: Restriction
  on property: is about
  some values from: PolyatomicEntity
definition: TUCAN is an identifier based on a canonicalization and serialization algorithm that is independent of domain-specific concepts of structure and bonding.
preferred label: TUCANDescriptor

absolute configuration stereochemical descriptor
type: Class
subclass of: stereochemical descriptor
creator: http://orcid.org/0000-0002-4378-6061
date: 2022-07-11T08:01:45+00:00
source: https://doi.org/10.1351/goldbook.A00020
definition: The spatial arrangement of the atoms of a chiral molecular entity (or group) and its stereochemical description e.g. R or S.
preferred label: AbsoluteConfigurationStereochemicalDescriptor

relative configuration stereochemical descriptor
type: Class
subclass of: stereochemical descriptor
creator: http://orcid.org/0000-0002-4378-6061
date: 2022-07-11T08:04:08+00:00
source: https://doi.org/10.1351/goldbook.R05260
definition: The configuration of any stereogenic (asymmetric) centre with respect to any other stereogenic centre contained within the same molecular entity. Unlike absolute configuration, relative configuration is reflection-invariant. Relative configuration, distinguishing diastereoisomers, may be denoted by the configurational descriptors R*, R* (or l) and R*, S* (or u) meaning, respectively, that the two centres have identical or opposite configurations. For molecules with more than two asymmetric centres the prefix rel- may be used in front of the name of one enantiomer where R and S have been used. If any centres have known absolute configuration then only R* and S* can be used for the relative configuration.
preferred label: RelativeConfigurationStereochemicalDescriptor

ACD/Labs index name
type: Class
subclass of: molecular entity name
IAO_0000118: index name
creator: http://orcid.org/0000-0002-4378-6061
date: 2022-07-11T08:20:10+00:00
source: https://www.acdlabs.com/products/name/
definition: A molecular entity name that represents the name of a molecular structure determined by the naming algorithms developed by ACD/Labs.
preferred label: ACDLabsIndexName

InChI with fixedH layer
type: Class
subclass of: InChI descriptor
creator: http://orcid.org/0000-0002-4378-6061
date: 2022-07-11T08:22:02+00:00
source: https://doi.org/10.1186%2Fs13321-015-0068-4
definition: An InChI descriptor that is not the standard and that is created with the fixedH layer option. The fixedH layer is appended to the standard InChI and lists the exact position of the tautomeric hydrogen atoms. It is useful when one wants to represent a specific tautomer of a given structure, because if the InChIs for the tautomers were created without the fixedH layer option, the normalization performed by the InChI generation program would result in these InChIs being identical.
preferred label: InChIWithFixedHLayer

ChEBIName
type: Class
subclass of: preferred name
IAO_0000115: A ChEBI name is a preferred name annotated by the ChEBI database. The ChEBI name has the additional feature that it is unique within the ChEBI dataset.
definition: ChEBI name

DrugTradeName
type: Class
subclass of: molecular entity name
IAO_0000115: Trade name of a drug compound.
definition: Drug trade name

InternationalNonMinusproprietaryName
type: Class
subclass of: molecular entity name
IAO_0000115: International Non-proprietary Name, defined by the WHO.
short name: INN
definition: International Non-proprietary Name

Unique Ingredient Identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
short name: UNII
definition: Identifier used by the USA Food and Drug Administration.
preferred label: UniqueIngredientIdentifier

LipidMaps identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Identifier used by the LipidMaps database, http://www.lipidmaps.org/.
preferred label: LipidMapsIdentifier

National Service Center number
type: Class
subclass of: ChemicalDatabaseIdentifier
short name: NSC number
definition: Identifier used by the Cancer Chemotherapy National Service Center.
preferred label: NationalServiceCenterNumber

RTECS identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Identifier used by the RTECS database (http://www.cdc.gov/niosh/rtecs/).
preferred label: RTECSIdentifier

European Registry of Materials identifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: Identifier used by the European Registry of Materials (https://nanocommons.github.io/identifiers/).
preferred label: EuropeanRegistryOfMaterialsIdentifier

SwissLipidsIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: SwissLipids identifier

MolMeDBIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: MolMeDB identifier

PDBLigandIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
definition: PDB ligand identifier

PDBStructureIdentifier
type: Class
subclass of: ChemicalDatabaseIdentifier
short name: PDB identifier
definition: PDB structure identifier

CHEMINF_000802
type: Class
subclass of: RuleOfFiveViolationsDescriptor
definition: Number of rule of five violations calculated by RDKit software library version 2015_09_2

CHEMINF_000803
type: Class
subclass of: hydrogen bond acceptor count
definition: Hydrogen bond acceptor count calculated by RDKit software library version 2015_09_2

CHEMINF_000804
type: Class
subclass of: hydrogen bond donor count
definition: Hydrogen bond donor count calculated by RDKit software library version 2015_09_2

CHEMINF_000805
type: Class
subclass of: logP descriptor
definition: LogP descriptor calculated by RDKit software library version 2015_09_2

CHEMINF_000806
type: Class
subclass of: molecular formula
definition: Molecular formula calculated by RDKit software library version 2015_09_2

CHEMINF_000807
type: Class
subclass of: average molecular weight descriptor
definition: Average molecular weight calculated by RDKit software library version 2015_09_2

CHEMINF_000808
type: Class
subclass of: PolarSurfaceAreaDescriptor
definition: Total polar surface area calculated by RDKit software library version 2015_09_2

Bond Polarizabilities
type: Class
subclass of: ElectronicDescriptor
subclass of: Restriction
  on property: is about
  some values from: MolecularEntity
definition: Descriptor that calculates the sum of the absolute value of the difference between atomic polarizabilities of all bonded atoms in the molecule (including implicit hydrogens).
preferred label: BondPolarizabilities

oxidation state
type: Class
subclass of: ElectronicDescriptor
subclass of: AtomicDescriptor
subclass of: Restriction
  on property: is about
  some values from: atom
source: https://doi.org/10.1351/goldbook.O04365
definition: Oxidation state is an atomic descriptor that gives the degree of oxidation of an atom in terms of counting electrons. The higher the oxidation state (OS) of a given atom, the greater is its degree of oxidation. [source: IUPAC Gold Book - https://doi.org/10.1351/goldbook.O04365]
preferred label: OxidationState

connectivity SMILES descriptor
type: Class
subclass of: SMILES descriptor
definition: A connectivity SMILES descriptor is a SMILES descriptor that does not include any stereochemical or isotopic information.
preferred label: ConnectivitySMILESDescriptor

BCUT
type: Class
subclass of: topological descriptor
doi: http://dx.doi.org/10.1021/ci980137x
short name: BCUT
definition: Eigenvalue based descriptor noted for its utility in chemical diversity.

bond partial pi charge
type: Class
subclass of: ElectronicDescriptor
short name: bondPartialPiCharge
definition: Descriptor that calculates bond-pi Partial charge of a bond by determining the difference the Partial Pi Charge on atoms A and B of a bond (based in Gasteiger Charge).
preferred label: BondPartialPiCharge

bond partial sigma charge
type: Class
subclass of: ElectronicDescriptor
short name: bondPartialSigmaCharge
definition: Descriptor that calculates bond-sigma Partial charge of a bond.
preferred label: BondPartialSigmaCharge

bond partial total charge
type: Class
subclass of: ElectronicDescriptor
short name: bondPartialTCharge
definition: Descriptor that calculates bond-total Partial charge of a bond.
preferred label: BondPartialTotalCharge

bond sigma electronegativity
type: Class
subclass of: ElectronicDescriptor
short name: bondSigmaElectronegativity
definition: Descriptor that calculates of bond-Polarizability of a bond by determining the difference the Sigma electronegativity on atoms A and B of a bond.
preferred label: BondSigmaElectronegativity

bonds to Atom
type: Class
subclass of: topological descriptor
short name: bondsToAtom
comment: This is the shortest distance between a pair of atoms in a graph, defined as the number of edges in the shortest path between the atom pair in the molecular graph.
definition: Descriptor based on the number of bonds on the shortest path between two atoms (topological distance).
preferred label: BondsToAtom

chi chain indices
type: Class
subclass of: topological descriptor
short name: chiChain
comment: It utilizes the graph isomorphism code of the CDK to find fragments matching SMILES strings representing the fragments corresponding to each type of chain.
definition: Evluates the simple and valence chi chain descriptors (Kier and Hall) of orders 3, 4, 5, 6 and 7.
preferred label: ChiChainIndices

chi cluster indices
type: Class
subclass of: topological descriptor
short name: chiCluster
comment: It utilizes the graph isomorphism code of the CDK to find fragments matching SMILES strings representing the fragments corresponding to each type of chain.
definition: Evluates the simple and valence chi cluster descriptors (Kier and Hall) of orders 3, 4,5 and 6.
preferred label: ChiClusterIndices

chi path indices
type: Class
subclass of: topological descriptor
short name: chiPath
comment: It utilizes the graph isomorphism code of the CDK to find fragments matching SMILES strings representing the fragments corresponding to each type of chain.
definition: Evaluates the Kier and Hall Chi path indices of orders 0,1,2,3,4,5,6 and 7.
preferred label: ChiPathIndices

chi path-cluster indices
type: Class
subclass of: topological descriptor
short name: chiPathCluster
comment: It utilizes the graph isomorphism code of the CDK to find fragments matching SMILES strings representing the fragments corresponding to each type of chain.
definition: Evaluates the Kier and Hall Chi path cluster indices of orders 4,5 and 6.
preferred label: ChiPathMinusclusterIndices

gravitational index
type: Class
subclass of: geometric descriptor
doi: http://dx.doi.org/10.1021/jp953224q
short name: gravitationalIndex
definition: Descriptor characterizing the mass distribution of the molecule.
preferred label: GravitationalIndex

gravitational index (square and cube roots)
type: Class
subclass of: gravitational index
doi: http://dx.doi.org/10.1021/ci980029a
short name: gravitationalIndex_SquareAndCubeRoots
definition: Descriptor characterizing the mass distribution of the molecule as the square or cube root of the gravitational index.
preferred label: GravitationalIndex(squareAndCubeRoots)

acceptor field atoms (Boehm,Klebe)
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1021/jm011039x
short name: hBondAcceptorsBoehmKlebe
definition: Counts the number of acceptor field atoms for a carbonyl oxygen probe using force field based definition.
preferred label: AcceptorFieldAtoms(Boehm,Klebe)

hydrogen bond acceptors (Daylight)
type: Class
subclass of: ElectronicDescriptor
short name: hBondacceptorsDaylight
comment: SMILES on-line tutorial, http://www.daylight.com/dayhtml_tutorials/languages/smarts/smarts_examples.html)
definition: Descriptor that calculates the number of hydrogen bond acceptors (by Daylight).
preferred label: HydrogenBondAcceptors(Daylight)

acceptors or donors field atoms (Boehm,Klebe)
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1021/jm011039x
short name: hBondAcceptorsDonorsBoehmKlebe
definition: Counts the number of acceptor/donor field atoms for a carbonyl oxygen or amino hydrogen probe.
preferred label: AcceptorsOrDonorsFieldAtoms(Boehm,Klebe)

donor field atoms (Boehm,Klebe)
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1021/jm011039x
short name: hBondDonorsBoehmKlebe
definition: Counts the number of donor field atoms for an amino hydrogen probe.
preferred label: DonorFieldAtoms(Boehm,Klebe)

hydrogen bond donors (Daylight)
type: Class
subclass of: ElectronicDescriptor
short name: hBondDonorsDaylight
comment: SMILES on-line tutorial, http://www.daylight.com/dayhtml_tutorials/languages/smarts/smarts_examples.html)
definition: Descriptor that calculates the number of hydrogen bond donors (by Daylight).
preferred label: HydrogenBondDonors(Daylight)

proton belonging to an aromatic system
type: Class
subclass of: ConstitutionalDescriptor
short name: isProtonInAromaticSystem
definition: Descriptor returns 1 if the protons is directly bonded to an aromatic system, it returns 2 if the distance between aromatic system and proton is 2 bonds, and it return 0 for other positions.
preferred label: ProtonBelongingToAnAromaticSystem

proton belonging to a pi-system
type: Class
subclass of: ConstitutionalDescriptor
short name: isProtonInConjugatedPiSystem
definition: Descriptor returns true if the protons is directly bonded to a pi system.
preferred label: ProtonBelongingToAPiMinussystem

Kier Hall SMARTS
type: Class
subclass of: topological descriptor
doi: http://dx.doi.org/10.3390/91201004
short name: kierHallSmarts
definition: Counts the number of occurrences of the E-state fragments.
preferred label: KierHallSMARTS

molecular distance edge
type: Class
subclass of: topological descriptor
doi: http://dx.doi.org/10.1021/ci970109z
short name: mde
definition: Evaluate molecular distance edge descriptors for C, N and O.
preferred label: MolecularDistanceEdge

moments of inertia
type: Class
subclass of: geometric descriptor
short name: momentOfInertia
definition: Descriptor that calculates the principal moments of inertia and ratios of the principal moments. Als calculates the radius of gyration.
preferred label: MomentsOfInertia

partial total charge (MMFF94)
type: Class
subclass of: ElectronicDescriptor
short name: partialTChargeMMFF94
definition: Descriptor that calculates total partial charges of an heavy atom.
preferred label: PartialTotalCharge(MMFF94)

period of an atom
type: Class
subclass of: ConstitutionalDescriptor
short name: period
definition: Descriptor that returns the period in the periodic table of an atom belonging to an atom container.
preferred label: PeriodOfAnAtom

pi-contact of two atoms
type: Class
subclass of: ConstitutionalDescriptor
short name: piContact
definition: Descriptor that check if two atoms have pi-contact (this is true when there is one and the same conjugated pi-system which contains both atoms, or directly linked neighboors of the atoms).
preferred label: PiMinuscontactOfTwoAtoms

proton total partial charge
type: Class
subclass of: ElectronicDescriptor
short name: protonPartialCharge
definition: Descriptor that calculates partial charges of an heavy atom and its protons based on Gasteiger Marsili (PEOE).
preferred label: ProtonTotalPartialCharge

RDF proton descriptor
type: Class
subclass of: topological descriptor
doi: http://dx.doi.org/10.1021/ac010737m
short name: rdfProtonCalculatedValues
comment: This is a mixed descriptor: topological, geometrical and electronic descriptor.
definition: Calculation of RDF proton descriptor.
preferred label: RDFProtonDescriptor

TAE RECON descriptors for amino acid sequences
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1016/0097-8485(94)00052-G
short name: taeAminoAcid
comment: {@cdk.cite BREN1995} {@cdk.cite BREN1997} {@cdk.cite WHITE2003}
definition: Descriptors are derived from pre-calculated quantum mechanical parameters by using the paramaters for amino acids and evaluating a set of 147 descriptors for peptide sequences.
preferred label: TAERECONDescriptorsForAminoAcidSequences

weighted path
type: Class
subclass of: topological descriptor
short name: weightedPath
definition: The weighted path (molecular ID) descriptors were described by Randic and they characterize molecular branching.
preferred label: WeightedPath

WHIM
type: Class
subclass of: topological descriptor
short name: WHIM
comment: Todeschini, R. and Gramatica, P.. New 3D Molecular Descriptors: The WHIM theory and QAR Applications, Persepectives in Drug Discovery and Design. 1998, pp. 355-380. Mixed descriptors: molecular size, shape, symmetry, and atom distribution and density. Uses 3D coordinates, PCA and it calculates 10 descriptors.
definition: Holistic descriptors described by Todeschini et al.

Moreau-Broto Autocorrelation (charge) descriptors
type: Class
subclass of: topological descriptor
short name: autoCorrelationCharge
comment: ATSc1 - ATSc5
definition: The Moreau-Broto autocorrelation descriptors using partial charges.

Moreau-Broto autocorrelation (mass) descriptors
type: Class
subclass of: topological descriptor
short name: autoCorrelationMass
comment: ATSm1 - ATSm5
definition: The Moreau-Broto autocorrelation descriptors using atomic weight.

Moreau-Broto autocorrelation (polarizability) descriptors
type: Class
subclass of: topological descriptor
short name: autoCorrelationPolarizability
comment: ATSp1 - ATSp5
definition: The Moreau-Broto autocorrelation descriptors using polarizability.

carbon types
type: Class
subclass of: topological descriptor
short name: carbonTypes
comment: C1SP1, C2SP1, C1SP2, C2SP2, C3SP2, C1SP3, C2SP3, C3SP3, C4SP3
definition: Characterizes the carbon connectivity in terms of hybridization
preferred label: CarbonTypes

carbon connectivity index (order 0)
type: Class
subclass of: topological descriptor
short name: chi0C
definition: Descriptor that calculates the carbon connectivity index (order 0).
preferred label: CarbonConnectivityIndex(order0)

valence connectivity index (order 0)
type: Class
subclass of: topological descriptor
short name: chi0v
definition: Descriptor that calculates atomic valence connectivity index (order 0).
preferred label: ValenceConnectivityIndex(order0)

valence carbon connectivity index (order 0)
type: Class
subclass of: topological descriptor
short name: chi0vC
definition: Descriptor that calculates carbon valence connectivity index (order 0).
preferred label: ValenceCarbonConnectivityIndex(order0)

carbon connectivity index (order 1)
type: Class
subclass of: topological descriptor
short name: chi1C
definition: Descriptor that calculates carbon connectivity index (order 1).
preferred label: CarbonConnectivityIndex(order1)

valence connectivity index (order 1)
type: Class
subclass of: topological descriptor
short name: chi1v
definition: Descriptor that calculates atomic valence connectivity index (order 1).
preferred label: ValenceConnectivityIndex(order1)

valence carbon connectivity index (order 1)
type: Class
subclass of: topological descriptor
short name: chi1vC
definition: Descriptor that calculates carbon valence connectivity index (order 1).
preferred label: ValenceCarbonConnectivityIndex(order1)

distance to atom
type: Class
subclass of: geometric descriptor
short name: distanceToAtom
definition: Descriptor that calculates the 3D distance between two atoms.
preferred label: DistanceToAtom

effective polarizability
type: Class
subclass of: ElectronicDescriptor
short name: effectivePolarizability
comment: EffectiveAtomPolarizabilityDescriptor, effAtomPol
definition: Descriptor that calculates the effective polarizability of a given heavy atom.
preferred label: EffectivePolarizability

hybridization ratio
type: Class
subclass of: topological descriptor
short name: hybratio
comment: It reports the fraction of sp3 carbons to sp2 carbons as Nsp3/ (Nsp3 + Nsp2). The original form of the descriptor (i.e., simple ratio) has been used to characterize molecular complexity, especially in the are of natural products , which usually have a high value of the sp3 to sp2 ratio. Other short names: HybridizationRatio, HybRatio.
definition: Characterizes molecular complexity in terms of carbon hybridization states.
preferred label: HybridizationRatio

Kier and Hall kappa molecular shape indices
type: Class
subclass of: topological descriptor
short name: kierValues
comment: Kier and Hall kappa molecular shape indices compare the molecular graph with minimal and maximal molecular graphs. First kappa shape index is given by n ( n - 1 ) 2 m 2 , second kappa shape index is given by ( n - 1 ) ( n - 2 ) 2 p 2 2 and third kappa shape index is given by ( n - 1 ) ( n - 3 ) 2 p 3 2 for odd n and ( n - 3 ) ( n - 2 ) 2 p 3 2 for enev n, where n denotes the number of atoms in the hydrogen suppressed graph, m is the number of bonds in the hydrogen suppressed graph. Also, let p2 denote the number of paths of length 2 and let p3 denote the number of paths of length 3. Other short names: KappaShapeIndices, Kier1, Kier2, Kier3.
definition: Descriptor that calculates Kier and Hall kappa molecular shape indices.
preferred label: KierAndHallKappaMolecularShapeIndices

partial pi charge
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1002/ange.19850970818
short name: partialPiCharge
comment: Other short_name: pepe.
definition: Descriptor that calculates pi partial charges in pi-bonded systems of an heavy atom based on based on Gasteiger H.Saller (PEPE).
preferred label: PartialPiCharge

partial sigma charge
type: Class
subclass of: ElectronicDescriptor
doi: http://dx.doi.org/10.1016/0040-4020(80)80168-2
short name: partialSigmaCharge
definition: Descriptor that calculates sigma partial charges in sigma-bonded systems (PEOE) of an heavy atom based on Gasteiger Marsili.
preferred label: PartialSigmaCharge

pi electronegativity
type: Class
subclass of: ElectronicDescriptor
short name: piElectronegativity
comment: Pi electronegativity is given by X = a + b q + c ( q 2 ) , where a, b and c are Gasteiger Marsili parameters, and q is the sigma charge. Other short_name: elecPiA.
definition: Descriptor that returns the pi electronegativity for a given atom.
preferred label: PiElectronegativity