An overlap expansion method for improving ab initio model potentials: Anisotropic intermolecular potentials of N₂, CO, and C₂H₂ with He*(2³S)

An overlap expansion (OE) method for improving intermolecular interaction potentials was proposed. Correction terms were introduced as a linear combination of squares of overlap integrals between interacting species, in order to include highly anisotopic interactions intrinsic to the molecular systems. As such, the present OE method was applied to improve crude potentials for intermolecular interactions between a molecule and a metastable atom.