gives True if bond is a bond in the molecule m, and False otherwise.


  • The bond may be a Bond or a list of two atom indices.
  • BondQ checks for the existence of a supported bond type in the molecule expression.
  • An unspecified bond order will match any bond type between the given atoms.
  • The list of atoms in bond is treated as orderless for the purposes of matching.


Basic Examples  (2)

Test whether single bonds are part of a molecule:

Test double bonds:

Introduced in 2019