OEFPAtomTypeΒΆ
This namespace contains atom typing options that can be used when generating Circular, Path of Tree fingerprints. Atom type options control how the atoms of the enumerated circular, path or tree fragments are encoded during the fingerprint generation.
The OEFPBondType namespace contains the following constants:
Note
The constants of the OEFPAtomType namespace can be combined using the bitwise OR operation.
Note
The images in this sections visualize the effect of the various atom typing options.
See also
- Visualizing Molecule Similarity section
See also
- OEFPBondType namespace
- OEMakeCircularFP function
- OEMakePathFP function
- OEMakeTreeFP function
- Atom and Bond Typing section
Note
All explicit hydrogens are suppressed of the molecule before generating any fingerprints. (See example in Example of molecules that are considered to be equivalent due to suppressing their explicit hydrogens).

Example of molecules that are considered to be equivalent due to suppressing their explicit hydrogens
AtomicNumber
This flag indicates that atomic number (the value returned by the OEAtomBase.GetAtomicNum method) is encoded into the generated fingerprint, i.e., if two fragments (either circular, paths or tree) are composed of atoms with different atomic numbers, then the two fragments will be mapped to different bits of the fingerprint. Table: Example of using the AtomicNumber option demonstrates the effect of using the OEFPAtomType.AtomicNumber flag.
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Aromaticity
This flag indicates that aromaticity (the value returned by the OEAtomBase.IsAromatic method) is encoded into the generated fingerprint, i.e., an aromatic and an aliphatic fragment will be mapped to different bits of the fingerprint. Table: Example of using the Aromatic option demonstrates the effect of using the OEFPAtomType.Aromaticity flag.
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Note
Prior to generating a fingerprint, the aromaticity of the molecule is re-perceived using the OEAroModel.OpenEye aromaticity model.
Chiral
This flag indicates that chiral and non-chiral atoms (the value returned by the OEAtomBase.IsChiral method) are distinguished during the fingerprint generation. Table: Example of using the Chiral option demonstrates the effect of using the OEFPAtomType.Chiral flag.
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Note
Different stereoisomers of molecules can not be distinguished when the OEFPAtomType.Chiral flag is set. (See example in Figure: Example of molecule similarity of stereoisomers).

Example of molecule similarity of stereoisomers
FormalCharge
This flag indicates that formal charge (the value returned by the OEAtomBase.GetFormalCharge method) is encoded into the generated fingerprint. Table: Example of using the FormalCharge option demonstrates the effect of using the OEFPAtomType.FormalCharge flag.
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HvyDegree
This flag indicates that heavy degree information (the value returned by the OEAtomBase.GetHvyDegree method) is encoded into the generated fingerprint. Table: Example of using the HvyDegree option demonstrates the effect of using the OEFPAtomType.HvyDegree flag.
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HCount
This flag indicates that number of hydrogens (the value returned by the OEAtomBase.GetTotalHCount method) is encoded into the generated fingerprint. Table: Example of using the HCount option demonstrates the effect of using the OEFPAtomType.HCount flag.
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Hybridization
This flag indicates that hybridization (the value returned by the OEAtomBase.GetHyb method) is encoded into the generated fingerprint. Table: Example of using the Hybridization option demonstrates the effect of using the OEFPAtomType.Hybridization flag.
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InRing
This flag indicates that atom topology (the value returned by the OEAtomBase.IsInRing method) is encoded into the generated fingerprint, i.e., if two fragments (either circular, path or tree) are composed of atoms with different atom topology, then the two fragments will be mapped to different bits of the fingerprint. Table: Example of using the InRing option demonstrates the effect of using the OEFPAtomType.InRing flag.
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EqAromatic
This flag modifies the meaning of the OEFPAtomType.AtomicNumber flag. If the OEFPAtomType.EqAromatic flag is set then aromatic atoms are considered equivalent during the fingerprint generation. Table: Example of using the EqAromatic option demonstrates the effect of using the OEFPAtomType.EqAromatic flag.
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EqHalogen
This flag modifies the meaning of OEFPAtomType.AtomicNumber flag. If the OEFPAtomType.EqHalogen flag is set then halide atoms (OEElemNo.F, OEElemNo.Cl, OEElemNo.Br, and OEElemNo.I) are considered equivalent during the fingerprint generation. Table: Example of using the EqHalogen option demonstrates the effect of using the OEFPAtomType.EqHalogen flag.
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EqHBondAcceptor
This flag modifies the meaning of the OEFPAtomType.AtomicNumber flag. If the OEFPAtomType.EqHBondAcceptor flag is set then atoms that are perceived as hydrogen bonding acceptors are considered equivalent during the fingerprint generation. The GraphSim TK uses the same definition as the MolProp TK to identify hydrogen bond acceptors. See examples in Figure: Molecules with hydrogen bond acceptor annotation. Table: Example of using the EqHBondAcceptor option demonstrates the effect of using the OEFPAtomType.EqHBondAcceptor flag.

Example of molecules with hydrogen bond acceptor annotation
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EqHBondDonor
This flag modifies the meaning of the OEFPAtomType.AtomicNumber flag. If the OEFPAtomType.EqHBondDonor flag is set then atoms that are perceived as hydrogen bonding donors are considered equivalent during the fingerprint generation. The GraphSim TK uses the same definition as the MolProp TK to identify hydrogen bond donors. See examples in Figure: Molecules with hydrogen bond donor annotation. Table: Example of using the EqHBondDonor option demonstrates the effect of using the OEFPAtomType.EqHBondDonor flag.

Molecules with hydrogen bond donor annotation
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DefaultAtom
Same as OEFPAtomType.DefaultPathAtom constant.
DefaultCircularAtom
The bitwise OR’d value of the following atom typing options:
- OEFPAtomType.AtomicNumber
- OEFPAtomType.Aromaticity
- OEFPAtomType.Chiral
- OEFPAtomType.FormalCharge
- OEFPAtomType.HCount
- OEFPAtomType.EqHalogen
See example in Figure: Circular fingerprint similarity with default circular atom and bond typing. This constant is used as atom typing parameter when a default Circular fingerprint is generated by the following functions:
- OEMakeFP (OEFingerPrint &, const OEMolBase &, OEFPType.Circular)
- OEMakeCircularFP (OEFingerPrint &, const OEMolBase &)
See also
- OEFPBondType.DefaultCircularBond constant

Circular fingerprint similarity with default circular atom and bond typing
DefaultCircularVSAtom
The default atom typing for the circular fingerprint that is designed for virtual screening. It is the same as DefaultCircularAtom without OEFPAtomType.FormalCharge.
DefaultPathAtom
The bitwise OR’d value of the following atom typing options:
- OEFPAtomType.AtomicNumber
- OEFPAtomType.Aromaticity
- OEFPAtomType.Chiral
- OEFPAtomType.FormalCharge
- OEFPAtomType.HvyDegree
- OEFPAtomType.Hybridization
- OEFPAtomType.EqHalogen
See example in Figure: Path fingerprint similarity with default path atom and bond typing. This constant is used as atom typing parameter when a default Path fingerprint is generated by the following functions:
- OEMakeFP (OEFingerPrint &, const OEMolBase &, OEFPType.Path)
- OEMakePathFP (OEFingerPrint &, const OEMolBase &)
See also
- OEFPBondType.DefaultPathBond constant

Path fingerprint similarity with default path atom and bond typing
DefaultPathVSAtom
The default atom typing for the path fingerprint that is designed for virtual screening. It is the same as DefaultPathAtom without OEFPAtomType.FormalCharge and OEFPAtomType.Hybridization.
DefaultTreeAtom
The bitwise OR’d value of the following atom typing options:
- OEFPAtomType.AtomicNumber
- OEFPAtomType.Aromaticity
- OEFPAtomType.Chiral
- OEFPAtomType.FormalCharge
- OEFPAtomType.HvyDegree
- OEFPAtomType.Hybridization
See example in Figure: Tree fingerprint similarity with default tree atom and bond typing. This constant is used as atom typing parameter when a default Tree fingerprint is generated by the following functions:
- OEMakeFP (OEFingerPrint &, const OEMolBase &, OEFPType.Tree)
- OEMakeTreeFP (OEFingerPrint &, const OEMolBase &)
See also
- OEFPBondType.DefaultTreeBond constant

Tree fingerprint similarity with default tree atom and bond typing
DefaultTreeVSAtom
The default atom typing for the tree fingerprint that is designed for virtual screening. It is the same as DefaultTreeAtom without OEFPAtomType.FormalCharge and OEFPAtomType.Hybridization.
None
No atom properties are encoded when generating a fingerprint.