Localized Molecular Orbitals for Polyatomic Molecules. III. Monocyclic Aromatic Rings.

摘要

Localized molecular orbitals (LMO's), which are useful for studies of chemical bonding, are especially interesting in comparisons within a homologous series of molecules. Here we generate and compare the LMO's for a series of monocyclic aromatic hydrocarbons. These LMO's are generated from canonical molecular orbitals (CMO's) by a unitary transformation which leaves invariant both the total energy and the total electronic density. This unitary transformation can be based on a number of internal criteria, for example, the Edmiston-Ruedenberg (ER) criterion, or that of Boys. Except for a few well-noted differences, these two criteria yield quantitatively similar results, and we use the latter criterion here because it is computationally much more efficient.