Polarizable QM/MM multiconfiguration self-consistent field approach with state-specific corrections: Environment effects on cytosine absorption spectrum
dc.contributor.author
dc.date.accessioned
2015-11-09T12:32:24Z
dc.date.available
2015-11-09T12:32:24Z
dc.date.issued
2015
dc.identifier.issn
1549-9618
dc.identifier.uri
dc.description.abstract
We present the formulation and implementation of a polarizable quantum mechanics/molecular mechanics (QM/MM) strategy to describe environment effects in multiconfiguration self-consistent field calculations. The strategy is applied to the calculation of the vertical absorption spectrum of cytosine in water. In our approach, mutual polarization of the solute and the solvent is solved self-consistently at the complete-active-space self-consistent-field (CASSCF) level, and the resulting set of charges and dipoles is used to calculate vertical excitation energies using the complete-active-space second-order perturbative (CASPT2) approach and its multistate (MS-CASPT2) variant. In order to treat multiple excited states, we converge the solvent polarization with respect to the state-averaged density of the solute. In order to obtain the final energies, however, we introduce a state-specific correction, where the solvent polarization is recomputed with the density of each state, and demonstrate that this correction brings the excitation energies closer to the values obtained with state-optimized orbitals. Comparison with PCM and nonpolarizable QM/MM calculations shows the importance of specific solute-solvent interactions and environment polarization in describing experiments. Overall, the calculated excitations for the π → π∗ states in water show good agreement with the experimental spectrum, whereas the n → π∗ appear at energies above 6 eV, approximately 1 eV higher than in the gas phase. Beyond solvents, the new method will allow studying the impact of heterogeneous biological environments in multiple excited states, as well as the treatment of multichromophoric systems where charge transfer and exciton states play important roles
dc.format.mimetype
application/pdf
dc.language.iso
eng
dc.publisher
American Chemical Society (ACS)
dc.relation
info:eu-repo/grantAgreement/MICINN//CTQ2011-26573/ES/MODELIZACION QUIMICO CUANTICA DE FOTOQUIMICA Y TRANSFERENCIA ELECTRONICA: SISTEMAS GRANDES, EFECTOS COLECTIVOS Y CONTROL OPTICO/
AGAUR/2014-2017/2014SGR1202
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Reproducció digital del document publicat a: http://dx.doi.org/10.1021/ct5010388
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© Journal of Chemical Theory and Computation, 2015, vol. 11, núm. 4, p. 1674-1682
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Articles publicats (D-Q)
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Tots els drets reservats
dc.title
Polarizable QM/MM multiconfiguration self-consistent field approach with state-specific corrections: Environment effects on cytosine absorption spectrum
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/embargoedAccess
dc.embargo.terms
Cap
dc.date.embargoEndDate
info:eu-repo/date/embargoEnd/2026-01-01
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.contributor.funder
dc.relation.ProjectAcronym
dc.identifier.eissn
1549-9626