Molecular d-orbital exponents for phosphonitriles and sulphonitriles determined by an exchange overlap variation. Part 1

Abstract

An optimization method for determining molecular orbital exponents is derived from the relationship between the two-centre, two-electron exchange integral and the two-centre, one-electron overlap integral, for a localized bond. This is called the exchange overlap variation (EOV) method. Molecular d-orbital sets for two variations of a π-bonding model for cyclic fluoro- and chlorophosphonitriles are determined and compared to the results of Mitchell's exchange energy optimization method for planar molecules (NPCl₂)₃, (NPF₂)₃ and (NPF₂)₄.