Finite-field Hartree-Fock calculations of atomic and molecular polarizabilities

The experiment of calculating atomic and molecular dipole polarizabilities within the Hartree-Fock approximation in the finite-field scheme is described. Small system (Li, Li-, li2, Li+2, Be) are selected to facilitate the use of extended basis sets. For Li- a very extensive set including a large number of diffuse and polarization functions is required to achieve a stable value. The results are compared with other theoretical and experimental data and are possibly within the accuracy of the Hartree-Fock model. The remaining error is essentially isolated as the correlation error. Inclusion of correlation is discussed and postponed to a later stage. (author)