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MoleculeMatchQ[mol,patt]

returns True if the Molecule matches the given pattern.

MoleculeMatchQ[patt]

represents an operator form of MoleculeMatchQ that can be applied to a molecule.

Details and Options
Details and Options Details and Options
Examples  
Basic Examples  
Options  
IgnoreIsotopes  
IgnoreStereochemistry  
See Also
Related Guides
History
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MoleculeMatchQ

MoleculeMatchQ[mol,patt]

returns True if the Molecule matches the given pattern.

MoleculeMatchQ[patt]

represents an operator form of MoleculeMatchQ that can be applied to a molecule.

Details and Options

Examples

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Basic Examples  (4)

Test whether two molecules match:

Wolfram Language code: MoleculeMatchQ[ Molecule[{"H", "H", "O"}, {Bond[{1, 3}, "Single"], Bond[{2, 3}, "Single"]}], Molecule[{"H", "O", "H"}, {Bond[{2, 1}, "Single"], Bond[{3, 2}, "Single"]}] ]

Test whether a molecule matches a formula:

Wolfram Language code: MoleculeMatchQ[ Molecule[{"C", "C", "C", "C", "C", "C", "H", "H", "H", "H", "H", "H"}, {Bond[{1, 2}, "Aromatic"], Bond[{2, 3}, "Aromatic"], Bond[{3, 4}, "Aromatic"], Bond[{4, 5}, "Aromatic"], Bond[{5, 6}, "Aromatic"], Bond[{6, 1}, "Aromatic"], Bond[{1, 7}, "Single"], Bond[{2, 8}, "Single"], Bond[{3, 9}, "Single"], Bond[{4, 10}, "Single"], Bond[{5, 11}, "Single"], Bond[{6, 12}, "Single"]}, {}], ChemicalFormula[{{"C", 6}, {"H", 6}}] ]

Test whether a molecule matches a pattern:

Wolfram Language code: MoleculeMatchQ[ Molecule[{"C", "C", "C", "C", "C", "C", "H", "H", "H", "H", "H", "H"}, {Bond[{1, 2}, "Aromatic"], Bond[{2, 3}, "Aromatic"], Bond[{3, 4}, "Aromatic"], Bond[{4, 5}, "Aromatic"], Bond[{5, 6}, "Aromatic"], Bond[{6, 1}, "Aromatic"], Bond[{1, 7}, "Single"], Bond[{2, 8}, "Single"], Bond[{3, 9}, "Single"], Bond[{4, 10}, "Single"], Bond[{5, 11}, "Single"], Bond[{6, 12}, "Single"]}, {}], MoleculePattern["a1aaaaa1"] ]

Use the operator form of MoleculeMatchQ to select chemical entities with a particular formula:

Wolfram Language code: Select[EntityList[[alkanes]], MoleculeMatchQ[ChemicalFormula[{"C" -> 6, "H" -> 14}]]]

Options  (2)

IgnoreIsotopes  (1)

By default, isotopologues do not match:

Wolfram Language code: MoleculeMatchQ[ Molecule[{"H", "O", "H"}, {Bond[{1, 2}, "Single"], Bond[{2, 3}, "Single"]}, {}], Molecule[{Atom["H", "MassNumber" -> 2], "O", Atom["H", "MassNumber" -> 2]}, {Bond[{1, 2}, "Single"], Bond[{2, 3}, "Single"]}, {}] ]

Use IgnoreIsotopesTrue to get a positive match:

Wolfram Language code: MoleculeMatchQ[ Molecule[{"H", "O", "H"}, {Bond[{1, 2}, "Single"], Bond[{2, 3}, "Single"]}, {}], Molecule[{Atom["H", "MassNumber" -> 2], "O", Atom["H", "MassNumber" -> 2]}, {Bond[{1, 2}, "Single"], Bond[{2, 3}, "Single"]}, {}], IgnoreIsotopes -> True ]

IgnoreStereochemistry  (1)

By default, stereoisomers do not match:

Wolfram Language code: MoleculeMatchQ[ Molecule["l-alanine"], Molecule["d-alanine"] ]

Use IgnoreStereochemistryTrue to get a positive match:

Wolfram Language code: MoleculeMatchQ[ Molecule["l-alanine"], Molecule["d-alanine"], IgnoreStereochemistry -> True ]
Wolfram Research (2021), MoleculeMatchQ, Wolfram Language function, https://reference.wolfram.com/language/ref/MoleculeMatchQ.html.

Text

Wolfram Research (2021), MoleculeMatchQ, Wolfram Language function, https://reference.wolfram.com/language/ref/MoleculeMatchQ.html.

CMS

Wolfram Language. 2021. "MoleculeMatchQ." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/MoleculeMatchQ.html.

APA

Wolfram Language. (2021). MoleculeMatchQ. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MoleculeMatchQ.html

BibTeX

@misc{reference.wolfram_2026_moleculematchq, author="Wolfram Research", title="{MoleculeMatchQ}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/MoleculeMatchQ.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_moleculematchq, organization={Wolfram Research}, title={MoleculeMatchQ}, year={2021}, url={https://reference.wolfram.com/language/ref/MoleculeMatchQ.html}, note=[Accessed: 13-June-2026]}