Dipole and quadrupole polarizabilities of Ni II and parameters of an effective potential for Ni I Rydberg states

Abstract

The relativistic configuration interaction method has been used to evaluate the bound and continuum portions of summation expressions for the dipole and quadrupole polarizabilities, yielding the Ni II results αD,0 = 7.686 au for 3d9 2D3/2 and αQ,0 = 61.940 au for 3d9 2D5/2. The experimental value for the latter is estimated to be 55(8) au. From the reduced matrix elements, we have evaluated the first non-adiabatic scalar dipole polarizability βD,0 for 2D5/2 to be 9.243 au (experimental estimate is 8.9 (1.2)) and the off-diagonal tensor dipole polarizability αD,2 to be = −0.220 au (experimental estimate is −0.04 au). Significant cancellations occur in this last quantity (see text).