Modified Electron-Pair Calculation on the Ground State of the Water Molecule with Accurate Integrals

Abstract

The modified electron-pair (MEP) and limited configuration interaction (CI) calculations are carried out on the ground state of H₂O with accurate integrals. The minimal Slater orbitals and Slater-type orbitals with optimized exponents are used as bases. It is concluded that the MEP approximation is a good compromise between simplicity and accuracy and is a valid substitute of a limited CI calculation.