Accurate Surface Chemistry beyond the Generalized Gradient Approximation: Illustrations for Graphene Adatoms

J Chem Theory Comput. 2013 Nov 12;9(11):4853-9. doi: 10.1021/ct400736w. Epub 2013 Oct 21.

Abstract

Simulations of surface chemistry often use density functional theory with generalized gradient approximations (GGAs) for the exchange-correlation functional. GGAs have well-known limitations for gas-phase chemistry, including underestimated reaction barriers, and are largely superseded by meta-GGAs and hybrids. Our simulations of O and Li adatoms on graphene add to a growing body of evidence that GGAs have similar limitations on surfaces and that meta-GGAs and screened hybrids are computationally feasible for such systems. Meta-GGAs and screened hybrids systematically improve accuracy, just as they do for gas-phase chemistry, motivating their continued exploration in surface chemistry.