Correlation consistent pseudopotentials for quantum Monte Carlo and other many-body electronic structure calculations: 3d transition elements.

We report on the construction and testing of pseudopotentials (PPs) for electronic structure calculations for 3d elements. This follows our recent work for the first and second rows. The construction emphasizes use of relativistic correlated calculations for the construction and simplicity of the resulting operators. Thorough testing in equilibrium and non-equilibrium conformations in molecular settings with hydride and oxide molecules is employed as the initial baseline for benchmarking and transferability tests of the constructions. The constructed PPs show small discrepancies for atomic and ionic excited states as well as consistently small discrepancies for molecular binding curves. The resulting potentials are smooth at the origin and of a semilocal form with a few gaussians per nonlocal channel. This allows their use also in plane wave codes with appropriately higher cut-offs. The PPs overall accuracy in explicitly correlated calculations is much higher than using nonrelativistic all-electron framework with explicit inlcusion of core states.