Study of potential curves by UHF-type methods. VI. Spin-extended Hartree–Fock method

An improved computational procedure of the spin-extended Hartree–Fock method is presented. The main features of the EHF potential curves for the dissociation of the LiH, BeH, and Li₂ molecules are discussed. The results are compared with curves calculated by the perturbation or CI methods using the same basis set.