Local correlation method for metals: benchmarks for surface and adsorption energies

TL;DR

This paper extends highly accurate coupled cluster methods within the method of increments to low-dimensional conducting systems, demonstrated on Mg surfaces and Xe adsorption, enabling precise energy calculations and analysis of correlation effects.

Contribution

It introduces an extension of the coupled cluster method of increments to low-dimensional conducting systems, with benchmarks on surface and adsorption energies.

Findings

Accurate surface energy calculations for Mg (0001) surface.

Precise adsorption energy for Xe on metal surface.

Method allows analysis of individual correlation-energy contributions.

Abstract

Highly accurate methods such as coupled cluster (CC) techniques can be used for periodic systems within the framework of the method of increments. Its extension to low-dimensional conducting system is considered. To demonstrate the presented approach a clean Mg (0001) surface is selected, where the CC treatment with single and double excitations and perturbative triples is used for calculation of the surface energy. Further example concerns the adsorption energy of Xe on the metal surface. The obtained results can be used to verify performance of the approximate methods. Along with the computational speed-up at the high-level of accuracy, application of the method of increments provides for a possibility to analyze influence of individual correlation-energy increments on the studied property.