Hartree-Fock-Roothaan calculations of dipolar polarizabilities for closed-shell atoms

Calculation of the dipole hyperpolarizability of atoms with closed and open shells by the Hartree-Fock-Roothaan method

“…(15) and values of the energy in the field, avoiding the calculation of α. It should be noted that the linear static polarizabilities obtained from the MFP agree very accurately with our calculations using strict BPT [7,9,10]. It would seem that the ideological simplicity and acceptable accuracy of the MFP makes it unnecessary to use the rather complicated perturbation theory for multielectron systems.…”

“…For this, any of the methods for minimizing functions of many variables is used. An analogous approach is used to optimize the SBS if an applied external electric field is used in the calculation of the linear polarizability of atoms [7,9,10]. In this instance, the criterion of maximum polarizability can be used because the linear polarizability of an atom in the ground state, according to the formulas of quantum-mechanical perturbation theory, is always strictly positive.…”