Evaluation of New Density Functional with Account of van der Waals Forces by Use of Experimental H2 Physisorption Data on Cu(111)

TL;DR

This paper evaluates a new density functional, vdW-DF2, that incorporates van der Waals forces, demonstrating its effectiveness in accurately modeling H2 physisorption on Cu(111) compared to experimental data.

Contribution

The study introduces and tests the vdW-DF2 functional, showing its improved accuracy in modeling physisorption potentials involving van der Waals interactions.

Findings

vdW-DF2 closely matches experimental physisorption energy curves

Indicates potential for further functional improvements

Supports the importance of nonlocal correlation effects

Abstract

Detailed experimental data for physisorption potential-energy curves of H2 on low-indexed faces of Cu challenge theory. Recently, density-functional theory has been developed to also account for nonlocal correlation effects, including van der Waals forces. We show that one functional, denoted vdW-DF2, gives a potential-energy curve promisingly close to the experiment-derived physisorptionenergy curve. The comparison also gives indications for further improvements of the functionals.