Third-order unitary coupled cluster (UCC3) for excited electronic states: efficient implementation and benchmarking
The efficient implementation of the third-order unitary coupled-cluster scheme (UCC3) for the calculation of excited electronic states is reported. The UCC3 scheme and its second-order UCC2 variant have been benchmarked and compared to Jacquemin’s recently introduced, as well as Thiel’s well-establi...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
12 May 2020
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| In: |
Journal of chemical theory and computation
Year: 2020, Volume: 16, Issue: 6, Pages: 3654-3663 |
| ISSN: | 1549-9626 |
| DOI: | 10.1021/acs.jctc.0c00335 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acs.jctc.0c00335
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| Author Notes: | Manuel Hodecker, Sebastian M. Thielen, Junzi Liu, Dirk R. Rehn, and Andreas Dreuw |
| Summary: | The efficient implementation of the third-order unitary coupled-cluster scheme (UCC3) for the calculation of excited electronic states is reported. The UCC3 scheme and its second-order UCC2 variant have been benchmarked and compared to Jacquemin’s recently introduced, as well as Thiel’s well-established, benchmark sets for excitation energies and oscillator strengths. For the latter, the calculation of 134 excited singlet and 71 excited triplet states of 28 small- to medium-sized organic molecules has revealed that UCC2 exhibits a mean error and standard deviation of 0.36 ± 0.41 eV for singlet states and 0.22 ± 0.21 eV for triplet states, whereas UCC3 revealed an accuracy of 0.06 ± 0.27 eV for singlet and −0.22 ± 0.15 eV for triplet states. In addition, the oscillator strengths obtained with effective transition moments correct through second order in perturbation theory are in very good agreement with literature data. |
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| Item Description: | Gesehen am 23.07.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1549-9626 |
| DOI: | 10.1021/acs.jctc.0c00335 |