Benchmarking CASPT3 Vertical Excitation Energies
| Title: | Benchmarking CASPT3 Vertical Excitation Energies |
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| Authors: | Boggio-Pasqua, Martial, Jacquemin, Denis, Loos, Pierre-François |
| Source: | J. Chem. Phys. 157, 014103 (2022) |
| Publication Year: | 2022 |
| Collection: | Condensed Matter Nuclear Theory Physics (Other) |
| Subject Terms: | Physics - Chemical Physics, Condensed Matter - Strongly Correlated Electrons, Nuclear Theory |
| More Details: | Based on 280 reference vertical transition energies of various natures (singlet, triplet, valence, Rydberg, $n\to\pi^*$, $\pi\to\pi^*$, and double excitations) extracted from the QUEST database, we assess the accuracy of third-order multireference perturbation theory, CASPT3, in the context of molecular excited states. When one applies the disputable ionization-potential-electron-affinity (IPEA) shift, we show that CASPT3 provides a similar accuracy as its second-order counterpart, CASPT2, with the same mean absolute error of $0.11$ eV. However, as already reported, we also observe that the accuracy of CASPT3 is almost insensitive to the IPEA shift, irrespective of the transition type and system size, with a small reduction of the mean absolute error to $0.09$ eV when the IPEA shift is switched off. Comment: 12 pages, 3 figures (supplementary material available) |
| Document Type: | Working Paper |
| DOI: | 10.1063/5.0095887 |
| Access URL: | http://arxiv.org/abs/2204.06480 |
| Accession Number: | edsarx.2204.06480 |
| Database: | arXiv |
| DOI: | 10.1063/5.0095887 |
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