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O: Fachverband Oberflächenphysik
O 82: Electronic Structure Theory I
O 82.1: Talk
Thursday, March 21, 2024, 10:30–10:45, MA 043
Black-box, accurate, and efficient prediction of band structures with Koopmans functionals — •Edward Linscott1, Nicola Colonna1, Junfeng Qiao2, and Nicola Marzari1,2 — 1Paul Scherrer Institut, Villigen, Switzerland — 2École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
Over the past fifteen years we have developed Koopmans functionals, a computationally efficient approach for predicting spectral properties in a functional framework.1 These orbital-density-dependent functionals impose a generalized piecewise linearity condition that ensures that orbital energies match the corresponding electron removal/addition total energy differences (in contrast to semi-local DFT, where a mismatch between the two lies at the heart of the band gap problem and the unreliability of Kohn-Sham band structures more generally). Koopmans functionals prove to be very powerful, yielding band structures and molecular orbital energies with comparable accuracy to self-consistent GW approaches but at greatly reduced computational cost and complexity.2 This talk will cover the theory of Koopmans functionals and how recent developments – namely, the development of automated workflows via the koopmans code3 and projectability-based Wannierization with manifold remixing4 – have brought us one step closer to black-box prediction of accurate band structures.
[1] Dabo et al., PRB 82 (2010), Borghi et al., PRB 90 (2014)
[2] Nguyen et al., PRX 8 (2018), Colonna et al., JCTC 15 (2019)
[3] koopmans-functionals.org, Linscott et al., JCTC 19 (2023)
[4] Qiao et al., npj Comput. Mater. 9, 206 & 208 (2023)
Keywords: Band structures; Wannier functions; Band gaps; Spectral functional theory; Orbital-density-dependent functional theory