Computed Ground State properties of BeO, MgO, CaO and SrO in Molecular Orbital Approximation

Abstract

Molecular properties of the four alkaline-earth oxides BeO, MgO, CaO and SrO in the ¹Σ ground state, computed in close to the Hartree-Fock approximation, are presented. Computed properties are total energies, dissociation energies, electric dipole and quadrupole moments, forces on the nucleus, field gradients at the nucleus and other mean values. Potential curves, spectroscopic constants, dipole moment function, μ(R), and variation of field gradients with internuclear separation are also presented and discussed. Although the computed sign of the dipole derivative dμ⁄dR at the equilibrium internuclear separation is negative only for MgO and positive for others, the fact that the computed sign for MgO and also the observed sign for SrO are negative suggests that dμ⁄dR for CaO may also have the negative sign. This indicates that the charge distribution in the alkaline-earth oxide can not be described by a simple polarizable ion-pair model. Crude estimates of magnetic properties of the molecules are made and discussed.