Assessment of the Tao-Mo nonempirical semilocal density functional in applications to solids and surfaces

Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract

Recently, Tao and Mo developed a semilocal exchange-correlation density functional. The exchange part of this functional is derived from a density-matrix expansion corrected to reproduce the fourth-order gradient expansion of the exchange energy in the slowly-varying-density limit, while the correlation part is based on the Tao-Perdew-Staroverov-Scuseria (TPSS) correlation functional, with a modification for the low-density limit. In the present paper, the Tao-Mo (TM) functional is assessed by computing various properties of solids and jellium surfaces. This includes 22 lattice constants and bulk moduli, 30 band gaps, seven cohesive energies, and jellium surface exchange and correlation energies for the density parameter rs in the range from 2 to 3 bohr. Our calculations show that the TM approximation can yield consistently high accuracy for most properties considered here, with mean absolute errors (MAEs) of 0.025 Å for lattice constants, 7.0 GPa for bulk moduli, 0.08 eV/atom for cohesive energies, and 35erg/cm2 for surface exchange-correlation energies. The MAE in band gaps is larger than that of TPSS, but slightly smaller than the errors of the local spin-density approximation, Perdew-Burke-Ernzerhof generalized gradient approximation, and revised TPSS. However, band gaps are still underestimated, particularly for large-gap semiconductors, compared to the Heyd-Scuseria-Ernzerhof nonlocal screened hybrid functional.

Description
Advisor
Degree
Type
Journal article
Keywords
Citation

Mo, Yuxiang, Car, Roberto, Staroverov, Viktor N., et al.. "Assessment of the Tao-Mo nonempirical semilocal density functional in applications to solids and surfaces." Physical Review B, 95, no. 3 (2017) American Physical Society: http://dx.doi.org/10.1103/PhysRevB.95.035118.

Has part(s)
Forms part of
Rights
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Link to license
Citable link to this page