A new generation of effective core potentials from correlated and spin-orbit calculations: selected heavy elements

We generate new correlation consistent effective core potentials (ccECPs) for the elements I, Bi, Ag, Au, Pd, Ir, Mo, Te and W with 4d, 5d, 6s and 6p valence spaces. These ccECPs are given as a sum of averaged spin-orbit (AREP) and effective spin-orbit (SO) terms. The construction involves several steps with increasing refinements in corresponding calculations of all-electron atoms using Coupled Cluster methods and optimizations of objective functions that include weighted atomic spectra, norm-conservations, spin-orbit effects and molecular binding curves for hydride and oxide dimers. The constructed ccECPs provide a consistent accuracy for valence-only calculations for these elements with significant improvements compared to previous tables. Our study confirms the importance of the AREP part in determining the overall accuracy in subsequent calculations such as trial wave functions in quantum Monte Carlo calculations.