Diffuse Basis Functions for Relativistic s and d Block Gaussian Basis Sets

Diffuse s, p, and d functions have been optimized for use with previously reported relativistic basis sets for the s and d blocks of the periodic table. The functions were optimized on the 4:1 weighted average of the s² and p² configurations of the anion, with the d shell in the d configuration for the d blocks. Exponents were extrapolated for groups 2 and 12, which have unstable or weakly bound anions. The diffuse basis sets have been tested by application to calculations of electron affinities of the group 11 elements (Cu, Ag, and Au), double electron affinities of the group 11 monocations, and potential energy curves of Mg₂ and Ca₂ van der Waals dimers, as well as some response properties of the group 1 anions (Rb^-, Cs^-, and Fr^-), the group 2 elements (Sr, Ba, and Ra), and RbLi, CsLi, and FrLi molecules.