Reference Energies for Double Excitations: Improvement and Extension
| Title: | Reference Energies for Double Excitations: Improvement and Extension |
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| Authors: | Kossoski, Fábris, Boggio-Pasqua, Martial, Loos, Pierre-François, Jacquemin, Denis |
| Source: | J. Chem. Theory Comput. 2024, 20, 5655-5678 |
| Publication Year: | 2024 |
| Collection: | Condensed Matter Nuclear Theory Physics (Other) |
| Subject Terms: | Physics - Chemical Physics, Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons, Nuclear Theory |
| More Details: | In the realm of photochemistry, the significance of double excitations (also known as doubly-excited states), where two electrons are concurrently elevated to higher energy levels, lies in their involvement in key electronic transitions essential in light-induced chemical reactions as well as their challenging nature from the computational theoretical chemistry point of view. Based on state-of-the-art electronic structure methods (such as high-order coupled-cluster, selected configuration interaction, and multiconfigurational methods), we improve and expand our prior set of accurate reference excitation energies for electronic states exhibiting a substantial amount of double excitations [http://dx.doi.org/10.1021/acs.jctc.8b01205; Loos et al. J. Chem. Theory Comput. 2019, 15, 1939]. This extended collection encompasses 47 electronic transitions across 26 molecular systems that we separate into two distinct subsets: (i) 28 "genuine" doubly-excited states where the transitions almost exclusively involve doubly-excited configurations and (ii) 19 "partial" doubly-excited states which exhibit a more balanced character between singly- and doubly-excited configurations. For each subset, we assess the performance of high-order coupled-cluster (CC3, CCSDT, CC4, and CCSDTQ) and multiconfigurational methods (CASPT2, CASPT3, PC-NEVPT2, and SC-NEVPT2). Using as a probe the percentage of single excitations involved in a given transition ($\%T_1$) computed at the CC3 level, we also propose a simple correction that reduces the errors of CC3 by a factor of 3, for both sets of excitations. We hope that this more complete and diverse compilation of double excitations will help future developments of electronic excited-state methodologies. Comment: 25 pages, 3 figures (Supporting Information available) |
| Document Type: | Working Paper |
| DOI: | 10.1021/acs.jctc.4c00410 |
| Access URL: | http://arxiv.org/abs/2403.19597 |
| Accession Number: | edsarx.2403.19597 |
| Database: | arXiv |
| DOI: | 10.1021/acs.jctc.4c00410 |
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