POLARIZABILITIES AND HYPERPOLARIZABILITIES OF THE ALKALI-METAL ATOMS

The electric static dipole polarizability alpha, quadrupole polarizability C, dipole-quadrupole polarizability B, and the second dipole hyperpolarizability gamma have been calculated for the alkali metal atoms in the ground state. The results are based on a pseudopotential which is able to incorporate the very important core-valence correlation effect through a core polarization potential, and, in an empirical way, the main relativistic effects. The calculated properties compare very well with mom elaborated calculations for the Li atom, excepting the second hyperpolarizability gamma. For the other atoms, there are neither theoretical nor experimental information about most of the higher polarizabilities. Hence, the results of this paper should be seen as a first attempt to give a complete account of the series expansion of the interaction energy of an alkali metal atom and a static electric field.