Electric properties of diatomic molecules: A comparison of finite basis set and finite difference Hartree-Fock calculations

Abstract

Recent work comparing the accuracy with which the electric properties of diatomic molecules can be obtained in the Hartree-Fock model from finite basis set (the algebraic approximation) and finite difference techniques is reviewed. The electric moments μ, Θ, Ω and Φ are considered together with the electric dipole polarizability α_zz and hyperpolarizability β_zzz. By comparing results obtained within the finite basis set approximation with those given by using finite difference techniques, accurate estimates of the basis set truncation errors corresponding to different electric properties of diatomic molecules can be gained. Accurate Hartree-Fock calculations of these electric properties are an essential prerequisite of precision correlation studies.