Assessing the accuracy of screened range-separated hybrids for bulk properties of semiconductors

Abstract

Density functional theory calculations using well-established semilocal and hybrid functionals are typically accurate for structural properties of semiconductors, but they often fail to quantitatively describe electronic-structure and optical properties of these materials. An improvement to conventional hybrid functionals is the class of screened range-separated hybrid (SRSH) functionals. In the SRSH approach, the range-separation parameter is used to empirically fit the band gap of the semiconductor, which was shown to lead to highly accurate predictions of electronic-structure and optical properties. Here we assess the accuracy of the SRSH approach for computing other important bulk properties of seven prototypical semiconductors, including lattice constants and phonon dispersion relations. Our SRSH results are compared to data from semilocal (PBE) and hybrid (HSE) functional calculations as well as to experimental data from the literature. We find that SRSH can compete with the high accuracy provided by the two well-established functionals PBE and HSE for computing bulk properties of semiconductors. Furthermore, similarly to the case of the HSE functional, the SRSH method yields phonon dispersion relations of semiconductors that tend to be more accurate than those calculated with PBE. The SRSH approach thus provides a consistently accurate framework for calculations of semiconductor bulk properties.