An overlap expansion method for improving ab initio model potentials: anisotropic intermolecular potentials of N2, CO, and C2H2 with He*(2(3)S)

Satoshi Maeda; Masakazu Yamazaki; Naoki Kishimoto; Koichi Ohno

doi:10.1063/1.1630954

An overlap expansion method for improving ab initio model potentials: anisotropic intermolecular potentials of N2, CO, and C2H2 with He*(2(3)S)

J Chem Phys. 2004 Jan 8;120(2):781-90. doi: 10.1063/1.1630954.

Authors

Satoshi Maeda¹, Masakazu Yamazaki, Naoki Kishimoto, Koichi Ohno

Affiliation

¹ Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan.

PMID: 15267914
DOI: 10.1063/1.1630954

Abstract

An overlap expansion method is proposed for improving ab initio model potentials. Correction terms are expanded in terms of overlap integrals between orbitals of the interacting system. The method is used to improve ab initio model potentials for N2+He*(2(3)S), CO+He*(2(3)S), and C2H2+He*(2(3)S). Physical meanings of the optimization are elucidated in terms of target orbitals. Correction terms are found to be dominated by the components of HOMO, LUMO, next-HOMO, and next-LUMO on the target molecule. The present overlap expansion method using a limited number of correction terms related to frontier orbitals provides an efficient and intuitive approach for construction of highly anisotropic intermolecular interaction potentials.