Exploring the accuracy of the equation-of-motion coupled-cluster band gap of solids

Author(s)
Evgeny Moerman, Henrique Miranda, Alejandro Gallo, Andreas Irmler, Tobias Schäfer, Felix Hummel, Manuel Engel, Georg Kresse, Matthias Scheffler, Andreas Grüneis
Abstract

While the periodic equation-of-motion coupled-cluster (EOM-CC) method promises systematic improvement of electronic band gap calculations in solids, its practical application at the singles and doubles level (EOM-CCSD) is hindered by severe finite-size errors in feasible simulation cells. We present a hybrid approach combining EOM-CCSD with the computationally less demanding GW approximation to estimate thermodynamic limit band gaps for several insulators and semiconductors. Our method substantially reduces required cell sizes while maintaining accuracy. Comparisons with experimental gaps and self-consistent GW calculations reveal that deviations in EOM-CCSD predictions correlate with reduced single excitation character of the excited many-electron states. Our work not only provides a computationally tractable approach to EOM-CC calculations in solids but also reveals fundamental insights into the role of single excitations in electronic-structure theory.

Organisation(s)
Computational Materials Physics
External organisation(s)
Fritz-Haber-Institut der Max-Planck-Gesellschaft, VASP Software GmbH, Technische Universität Wien
Journal
Physical Review B
Volume
111
No. of pages
7
ISSN
2469-9950
DOI
https://doi.org/10.48550/arXiv.2501.18667
Publication date
03-2025
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics, 103015 Condensed matter
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/ecdef07d-a4bc-4d7b-9b39-32f855a5f8de