All-Electron Scalar Relativistic Basis Sets for the Actinides

Increasing interest in the computational modeling of actinide compounds creates the need for alternative choices when in comes to fine tuning the computational methodology in order to best fit the problem at hand. All-electron scalar relativistic density functional theory can be a useful approach for a variety of actinide systems and would benefit from atomic basis sets geared to that level of theory. In this paper we present segmented all-electron relativistically contracted (SARC) basis sets for the complete actinide series Ac-89-Lr-103, optimized for use with the popular Douglas-Kroll-Hess to the second order and zeroth-order regular approximation scalar relativistic Hamiltonians. The quality of the SARC basis sets is assessed in terms of their intrinsic incompleteness and contraction errors, with respect to total energies, orbital properties, and ionization energies. Calculations on diatomic Ac and Lr molecules confirm that the valence-space construction results in negligible basis set superposition errors. The performance of the basis sets is further evaluated for molecular geometries, vibrational frequencies, and bond dissociation energies in an illustrative study of uranium fluorides UFn (n = 1-6).