Determination of the optimal energy denominator shift parameter of KRb electronic states in quantum chemical computations using perturbation theory

Abstract

The infl uence of the energy denominator shift (EDS) parameter and the quantitative and qualitative compositions of electronic states included in CASSCF(2,14)/XMCQDPT2 ab initio calculations of the ground state equilibrium internuclear distance and dissociation energy of polar KRb was determined