We have carried out calculations of multipole polarizabilities of helium and the hydrogen negative ion interacting with pure Coulomb and screened Coulomb potentials using highly accurate correlated exponential wave functions with exponent generated by a quasirandom process. The dipole, quadrupole, and octupole polarizabilities for the ground $1s^2$ ${{}^{1}S}^{\text{e}}$ state for different screening parameters starting from infinity (pure Coulomb case) to small values of the screening parameters, are reported. The octupole polarizability of the hydrogen negative ion is reported for the first time in the literature. The bound $4{}^{1}F$ state energy of helium for different screening parameters are also reported.

• Received 9 October 2009

DOI:https://doi.org/10.1103/PhysRevA.80.062511