Electric dipole polarizabilities of negative ions of the coinage metal atoms

Abstract

The dipole polarizability of the coinage metal anions is calculated in different approximations for both the electron correlation and relativistic effects. The large polarizabilities of these ions give a good illustration of the performance of different computational methods. The spin-averaged Douglas-Kroll no-pair scheme combined with the CCSD(T) treatment of the electron correlation predict the following values of polarizabilities: 243 au for Cu −, 213 au for Ag − and only about 93 au for Au −. The non-relativistic CCSD(T) results are 278, 299 and 256 au, respectively. Both the non-relativistic and relativistic results agree with the QCISD(T) pseudopotential data, though serious discrepancies occur at the level of the QCISD approximation. The use of the scalar Pauli approximation for the estimation of the relativistic contribution to the dipole polarizabilities of the coinage metal ions is limited to Cu − and Ag −. For Au − this approximation strongly overestimates the magnitude of the relativistic effect.