Valence basis sets for relativistic energy-consistent small-core actinide pseudopotentials

Abstract

Gaussian (14s13p10d8f6g)/[6s6p5d4f3g] atomic natural orbital valence basis sets have been generated for relativistic energy-consistent small-core actinide pseudopotentials of the Stuttgart–Bonn variety. Effective valence spin–orbit operators supplementing the scalar-relativistic pseudopotentials have been derived from multiconfiguration Dirac–Hartree–Fock reference data. Pseudopotentials, basis sets and spin–orbit operators have been used to determine the first and second ionization potentials of all actinide elements at the multiconfiguration self-consistent field and multireference averaged coupled-pair functional level. Comparison is made to results obtained from large-scale calculations using uncontracted basis sets up to i-type functions and extrapolation to the basis set limit as well as to experimental data. Molecular calibration studies using the coupled-cluster singles, doubles, and perturbative triples approach are reported for the ground states of AcH, AcO, AcF, and ThO.