The random phase approximation applied to solids, molecules, and graphene-metal interfaces: From weak to strong binding regimes

TL;DR

This paper demonstrates the effectiveness of the random phase approximation (RPA) in accurately modeling a wide range of systems, from weak van der Waals interactions to strong covalent bonds, especially in metal-organic interfaces.

Contribution

The study applies plane wave-based RPA calculations to diverse systems, highlighting its ability to capture both dispersive and covalent interactions better than other density functionals.

Findings

RPA accurately models graphene-metal interfaces.

RPA captures both weak and strong interactions effectively.

Benchmarking shows RPA's limitations with delocalization errors.

Abstract

The random phase approximation (RPA) is attracting renewed interest as a universal and accurate method for first-principles total energy calculations. The RPA naturally accounts for long-range dispersive forces without compromising accuracy for short range interactions making the RPA superior to semi-local and hybrid functionals in systems dominated by weak van der Waals or mixed covalent-dispersive interactions. In this work we present plane wave-based RPA calculations for a broad collection of systems with bond types ranging from strong covalent to van der Waals. Our main result is the RPA potential energy surfaces of graphene on the Cu(111), Ni(111), Co(0001), Pd(111), Pt(111), Ag(111), Au(111), and Al(111) metal surfaces, which represent archetypical examples of metal-organic interfaces. Comparison with semi-local density approximations and a non-local van der Waals functional show that only the RPA captures both the weak covalent and dispersive forces which are equally important for these systems. We benchmark our implementation in the GPAW electronic structure code by calculating cohesive energies of graphite and a range of covalently bonded solids and molecules as well as the dissociation curves of H2 and H2+. These results show that RPA with orbitals from the local density approximation suffers from delocalization errors and systematically underestimates covalent bond energies yielding similar or lower accuracy than the Perdew-Burke-Ernzerhof (PBE) functional for molecules and solids, respectively.