DENSITY-FUNCTIONAL CALCULATIONS OF ELECTRIC-DIPOLE POLARIZABILITIES FOR ATOMS

Static electric-dipole polarizabilities for closed-shell atoms and positive ions are calculated directly from the ground-state densities of these systems. Calculations are performed using the variational principle for the energy by making an ansatz for the change in the density when the atom is put in an electric field. Since the energies are calculated from the density, the kinetic and the exchange-correlation energies have to be approximated. The exchange-correlation energy is taken within the local-density approximation. To calculate the changes in the ground-state energies accurately, we suggest the use of a kinetic-energy functional of the density which is particularly suited for such situations where the changes in the energy are of importance.