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arXiv · 2409.03721

Finite-size Effects in periodic EOM-CCSD for Ionization Energies and Electron Affinities: Convergence Rate and Extrapolation to the Thermodynamic Limit

Evgeny Moerman·Alejandro Gallo·Andreas Irmler·Tobias Schäfer·Felix Hummel·Andreas Grüneis·Matthias Scheffler
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Abstract

We investigate the convergence of quasi-particle energies for periodic systems to the thermodynamic limit using increasingly large simulation cells corresponding to increasingly dense integration meshes in reciprocal space. The quasi-particle energies are computed at the level of equation-of-motion coupled-cluster theory for ionization (IP-EOM-CC) and electron attachment processes (EA-EOM-CC). By introducing an electronic correlation structure factor, the expected asymptotic convergence rates for systems with different dimensionality are formally derived. We rigorously test these derivations through numerical simulations for trans-Polyacetylene using IP/EA-EOM-CCSD and the G0W0@HF approximation, which confirm the predicted convergence behavior. Our findings provide a solid foundation for efficient schemes to correct finite-size errors in IP/EA-EOM-CCSD calculations.

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Evgeny Moerman, Alejandro Gallo, Andreas Irmler, Tobias Schäfer, Felix Hummel, Andreas Grüneis, Matthias Scheffler. 2024-09-05. Finite-size Effects in periodic EOM-CCSD for Ionization Energies and Electron Affinities: Convergence Rate and Extrapolation to the Thermodynamic Limit. https://doi.org/10.1021/acs.jctc.4c01451

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