Correlated Electron Pseudopotentials for 3d-Transition Metals

TL;DR

This paper introduces new correlated electron pseudopotentials for 3d-transition metals, incorporating relativistic effects, and demonstrates their improved accuracy over existing pseudopotentials in molecular calculations.

Contribution

The authors adapt the CEPPs method for 3d-transition metals, including relativistic effects, and validate their accuracy against all-electron CCSD(T) calculations.

Findings

CEPPs outperform Hartree-Fock pseudopotentials in accuracy.

CEPPs accurately reproduce dissociation energies and geometries.

Relativistic effects are successfully incorporated into CEPPs.

Abstract

A recently published correlated electron pseudopotentials (CEPPs) method has been adapted for application to the 3d-transition metals, and to include relativistic effects. New CEPPs are reported for the atoms Sc$-$Fe, constructed from atomic quantum chemical calculations that include an accurate description of correlated electrons. Dissociation energies, molecular geometries, and zero-point vibrational energies of small molecules are compared with all electron results, with all quantities evaluated using coupled cluster singles doubles and triples (CCSD(T)) calculations. The CEPPs give better results in the correlated-electron calculations than Hartree-Fock-based pseudopotentials available in the literature.