A
valence-shell atomic orbital whose derivation involves diagonalising the localized
block of the full density matrix of a given molecule associated with basis functions
on that atom. A distinguishing feature of
NAOs is that they meet the simultaneous requirement of orthonormality and maximum occupancy.
For isolated atoms,
NAOs coincide with natural orbitals. In a polyatomic molecule the
NAOs (in contrast to natural orbitals that become delocalised over all nuclear centres)
mostly retain one-centre character, and thus are optimal for describing the molecular
electron density around each atomic centre.
Source:
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
