Shape and Energy Consistent Pseudopotentials for Correlated Electron systems

Abstract

A method is developed for generating pseudopotentials for use in correlated-electron calculations. The paradigms of shape and energy consistency are combined and defined in terms of correlated-electron wave-functions. The resulting energy consistent correlated electron pseudopotentials (eCEPPs) are constructed for H, Li--F, Sc--Fe, and Cu. Their accuracy is quantified by comparing the relaxed molecular geometries and dissociation energies they provide with all electron results, with all quantities evaluated using coupled cluster singles doubles and triples calculations. Errors inherent in the pseudopotentials are also compared with those arising from a number of approximations commonly used with pseudopotentials. The eCEPPs provide a significant improvement in optimised geometries and dissociation energies for small molecules, with errors for the latter being an order-of-magnitude smaller than for Hartree-Fock-based pseudopotentials available in the literature. Gaussian basis sets are optimised for use with these pseudopotentials.