SEST: Simulated Electronic Structure Theory.

A novel approach to empirically modeling the electronic structure of molecules is introduced. The theory is based on relationships between molecular orbital energy components and the average distance between electrons and electrons and nuclei. The electron-electron and electron-nucleus distances are subsequently related to interatomic distances which provides a means for modeling the electronic structure of molecules. The general energy expression for a simulated electronic structure theory is defined, along with the functional form of the interatomic distance dependent energy functions. The theory is used to model the hydrogen molecule, the first-row hydrides, and ethane. The models, which have the correct RHF/6-31G(d) optimized geometries, also fit the RHF/6-31G(d) energy at equilibrium and the UHF/6-31G(d) energy at the bond dissociation limit as well as some vibrational frequencies.