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Physical review. B, Condensed matter

Description of exchange and correlation in the strongly inhomogeneous electron gas using a nonlocal density functional

Philip P. Rushton, David J. Tozer, Stewart J. Clark

Published May 2, 2002• 22 citations
Publisher

Abstract

We present exchange-correlation energy densities ${e}_{\mathrm{xc}},$ total energies ${E}_{\mathrm{xc}},$ and holes, calculated for strongly inhomogeneous electron gases using the nonlocal weighted density approximation. The results closely resemble variational Monte Carlo simulations performed recently [Phys. Rev. Lett. 87, 036401 (2001)], demonstrating the effectiveness of a nonlocal density functional description.

DOI
10.1103/physrevb.65.193106

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We present exchange-correlation energy densities exc,{e}_{\mathrm{xc}},exc​, total energies Exc,{E}_{\mathrm{xc}},Exc​, and holes, calculated for strongly inhomogeneous electron gases using the nonlocal weighted density approximation. The results closely resemble variational Monte Carlo simulations performed recently [Phys. Rev. Lett. 87, 036401 (2001)], demonstrating the effectiveness of a nonlocal density functional description.
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Accurate treatment of the electronic correlation in inhomogeneous electronic systems, combined with the ability to capture the correlation energy of the homogeneous electron gas, allows to reach high predictive power in the application of density-functional theory. For two-dimensional systems we can achieve this goal by generalizing our previous approximation [Phys. Rev. B 79, 085316 (2009)] to a parameter-free form, which reproduces the correlation energy of the homogeneous gas while preserving the ability to deal with inhomogeneous systems. The resulting functional is shown to be very accurate for finite systems with an arbitrary number of electrons with respect to numerically exact reference data.
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