Effect of arbitrary small perturbation on atomic hydrogen polarizability

Using the Sturm expansion of the Coulomb Green's function, the effect of arbitrary weak static perturbation on the polarizability of a nonrelativistic hydrogen atom in the ground state was studied. It was shown that the corrections to the polarizability tensor in the lowest order of perturbation theory contain a small number of matrix elements with respect to the Sturm functions of the components V/sub l//sub m/ of the perturbing potential with l = 0 and 2. The efficiency of the approach is demonstrated by examples of perturbation by an eliminated Coulomb center, a spherically symmetric electron cloud and a magnetic field