Contracted Gaussian basis sets for Douglas-Kroll-Hess calculations: Estimating scalar relativistic effects of some atomic and molecular properties

Douglas-Kroll-Hess (DKH) contracted Gaussian basis sets of double, triple, and quadruple zeta valence qualities plus polarization functions ( X ZP , X = D , T, and Q, respectively) for the atoms H-Ar and DZP and TZP for K-Kr are presented. They have been determined from the corresponding nonrelativistic basis sets generated previously by Jorge We have recontracted the original X ZP basis sets, i.e., the values of the contraction coefficients were reoptimized using the relativistic DKH Hamiltonian. The effect of DKH at the coupled-cluster level of theory on the ionization energy of some atoms and dissociation energy and geometric parameters for a sample of molecules is discussed. Our results were compared with theoretical and experimental values reported in the literature.