Band gaps of crystalline solids from Wannier-localization-based optimal tuning of a screened range-separated hybrid functional

Journal article

Accurate prediction of fundamental band gaps of crystalline solid-state systems entirely within density functional theory is a long-standing challenge. Here, we present a simple and inexpensive method that achieves this by means of nonempirical optimal tuning of the parameters of a screened range-separated hybrid functional. The tuning involves the enforcement of an ansatz that generalizes the ionization potential theorem to the removal of an electron from an occupied state described by a localized Wannier function in a modestly sized supercell calculation. The method is benchmarked against experiment for a set of systems ranging from narrow band-gap semiconductors to large band-gap insulators, spanning a range of fundamental band gaps from 0.2 to 14.2 electronvolts (eV), and is found to yield quantitative accuracy across the board, with a mean absolute error of ∼0.1 eV and a maximal error of ∼0.2 eV.

Authors: Wing, D; Ohad, G; Haber, JB; Filip, MR; Gant, SE

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: National Academy of Sciences
• Journal: Proceedings of the National Academy of Sciences
• Volume: 118
• Issue: 34
• Article number: e2104556118
• Publication date: 2021-08-24
• Acceptance date: 2021-07-16
• DOI: 10.1073/pnas.2104556118
• EISSN: 1091-6490
• ISSN: 0027-8424
• Pmid: 34417292
• Language: English
• Keywords: band gap; density functional theory; optimal tuning; FFR