Adjustment of Ab Initio Potential Curves

Abstract

A semiempirical method of adjusting ab initio diatomic molecule potential curves is described. The adjusted curve gives the exact result in the separated‐ and united‐atom limits and also has correct asymptotic behavior in these limits. Different adjustment procedures are considered. At present, we favor the so‐called ``pseudokinetic‐energy'' adjustment procedure in which pseudokinetic energies are calculated from the virial formula. This procedure is applied to several ab initio potentials for He₂ (1s², 1s2s, ³Σ_u⁺).