An electrically neutral entity consisting of more than one atom (\(n>1\)). Rigorously, a molecule, in which \(n>1\) must correspond to a depression on the potential energy surface that is deep enough to confine at least one vibrational state.
See also:
molecular entity
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1143 [Terms] [Paper]