ELECTRIC-DIPOLE POLARIZABILITIES FOR HELIUM-LIKE IONS FROM CORRELATED WAVE-FUNCTIONS - A DENSITY-FUNCTIONAL APPROACH

Static electric dipole polarizabilities for helium-like ions H-, He, Li+, Be2+, B3+, and Ne8+ are calculated from their respective Hylleraas wavefunctions. However, instead of using the wavefunctions directly, we employ the corresponding densities in a density-based approach proposed recently (by Harbola) for calculating polarizabilities. The only approximation made is that of the local density for the exchange and correlation energy functionals. The use of density makes our calculations much simpler than those based on the wavefunctions. They lead however to essentially the same results as the wavefunctional calculations in cases where the results are known.