Interatomic and intraatomic analysis of the density matrix: applications to chlorobenzenes

Abstract

Bond orders and valence indices have been evaluated employing Mayer's definitions with orthogonalized atomic orbitals (OAO) obtained from Löwdin orthogonalization over an STO-3G basis set in an ab initio formalism. It has been observed that the eigenvalues of the submatrices associated with bond order orbitals. natural hybrid orbitals and natural bond orbitals also reproduce the same values of the bond orders and the valence indices which in turn are quite close to the classical values. Bond orders obtained by a similarity transformation of the ab initio density matrix differ appreciably in numerical magnitude.