On the Bond Order between Atoms in Approximate SCF-MO Theory

Abstract

The bond order between two atoms is discussed within the framework of all-valence-electron SCF-MO theories based on the Zero-Differential Overlap Approximation, and a definition of the bond order is proposed which is analogous to the procedure used to extract charge distributions from approximate SCF-MO calculations. Bond orders are calculated for a variety of small molecules and relationships similar to those found in π-electron theory between bond lengths and bond orders are observed. CNDO wave functions are used in this work, although the definition may also be used for calculations based on the INDO and NDDO approximations.