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Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods
[Image: see text] The ability to accurately compute low-energy excited states of chlorophylls is critically important for understanding the vital roles they play in light harvesting, energy transfer, and photosynthetic charge separation. The challenge for quantum chemical methods arises both from th...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical
Society
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584356/ https://www.ncbi.nlm.nih.gov/pubmed/32930590 http://dx.doi.org/10.1021/acs.jpcb.0c05761 |
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author | Sirohiwal, Abhishek Berraud-Pache, Romain Neese, Frank Izsák, Róbert Pantazis, Dimitrios A. |
author_facet | Sirohiwal, Abhishek Berraud-Pache, Romain Neese, Frank Izsák, Róbert Pantazis, Dimitrios A. |
author_sort | Sirohiwal, Abhishek |
collection | PubMed |
description | [Image: see text] The ability to accurately compute low-energy excited states of chlorophylls is critically important for understanding the vital roles they play in light harvesting, energy transfer, and photosynthetic charge separation. The challenge for quantum chemical methods arises both from the intrinsic complexity of the electronic structure problem and, in the case of biological models, from the need to account for protein–pigment interactions. In this work, we report electronic structure calculations of unprecedented accuracy for the low-energy excited states in the Q and B bands of chlorophyll a. This is achieved by using the newly developed domain-based local pair natural orbital (DLPNO) implementation of the similarity transformed equation of motion coupled cluster theory with single and double excitations (STEOM-CCSD) in combination with sufficiently large and flexible basis sets. The results of our DLPNO–STEOM-CCSD calculations are compared with more approximate approaches. The results demonstrate that, in contrast to time-dependent density functional theory, the DLPNO–STEOM-CCSD method provides a balanced performance for both absorption bands. In addition to vertical excitation energies, we have calculated the vibronic spectrum for the Q and B bands through a combination of DLPNO–STEOM-CCSD and ground-state density functional theory frequency calculations. These results serve as a basis for comparison with gas-phase experiments. |
format | Online Article Text |
id | pubmed-7584356 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | American Chemical
Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-75843562020-10-26 Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods Sirohiwal, Abhishek Berraud-Pache, Romain Neese, Frank Izsák, Róbert Pantazis, Dimitrios A. J Phys Chem B [Image: see text] The ability to accurately compute low-energy excited states of chlorophylls is critically important for understanding the vital roles they play in light harvesting, energy transfer, and photosynthetic charge separation. The challenge for quantum chemical methods arises both from the intrinsic complexity of the electronic structure problem and, in the case of biological models, from the need to account for protein–pigment interactions. In this work, we report electronic structure calculations of unprecedented accuracy for the low-energy excited states in the Q and B bands of chlorophyll a. This is achieved by using the newly developed domain-based local pair natural orbital (DLPNO) implementation of the similarity transformed equation of motion coupled cluster theory with single and double excitations (STEOM-CCSD) in combination with sufficiently large and flexible basis sets. The results of our DLPNO–STEOM-CCSD calculations are compared with more approximate approaches. The results demonstrate that, in contrast to time-dependent density functional theory, the DLPNO–STEOM-CCSD method provides a balanced performance for both absorption bands. In addition to vertical excitation energies, we have calculated the vibronic spectrum for the Q and B bands through a combination of DLPNO–STEOM-CCSD and ground-state density functional theory frequency calculations. These results serve as a basis for comparison with gas-phase experiments. American Chemical Society 2020-09-15 2020-10-08 /pmc/articles/PMC7584356/ /pubmed/32930590 http://dx.doi.org/10.1021/acs.jpcb.0c05761 Text en This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. |
spellingShingle | Sirohiwal, Abhishek Berraud-Pache, Romain Neese, Frank Izsák, Róbert Pantazis, Dimitrios A. Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods |
title | Accurate Computation of the Absorption Spectrum of
Chlorophyll a with Pair Natural Orbital Coupled Cluster
Methods |
title_full | Accurate Computation of the Absorption Spectrum of
Chlorophyll a with Pair Natural Orbital Coupled Cluster
Methods |
title_fullStr | Accurate Computation of the Absorption Spectrum of
Chlorophyll a with Pair Natural Orbital Coupled Cluster
Methods |
title_full_unstemmed | Accurate Computation of the Absorption Spectrum of
Chlorophyll a with Pair Natural Orbital Coupled Cluster
Methods |
title_short | Accurate Computation of the Absorption Spectrum of
Chlorophyll a with Pair Natural Orbital Coupled Cluster
Methods |
title_sort | accurate computation of the absorption spectrum of
chlorophyll a with pair natural orbital coupled cluster
methods |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7584356/ https://www.ncbi.nlm.nih.gov/pubmed/32930590 http://dx.doi.org/10.1021/acs.jpcb.0c05761 |
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