QM/MM Car-Parrinello molecular dynamics study of the solvent effects on the ground state and on the first excited singlet state of acetone in water.

Détails

ID Serval
serval:BIB_8F286B58AD27
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
QM/MM Car-Parrinello molecular dynamics study of the solvent effects on the ground state and on the first excited singlet state of acetone in water.
Périodique
ChemPhysChem
Auteur⸱e⸱s
Röhrig U.F., Frank I., Hutter J., Laio A., VandeVondele J., Rothlisberger U.
ISSN
1439-4235 (Print)
ISSN-L
1439-4235
Statut éditorial
Publié
Date de publication
2003
Peer-reviewed
Oui
Volume
4
Numéro
11
Pages
1177-1182
Langue
anglais
Résumé
We present a hybrid Car-Parrinello quantum mechanical/molecular mechanical (QM/MM) approach that is capable of treating the dynamics of molecular systems in electronically excited states in complex environments. The potential energy surface in the excited state is described either within the restricted open-shell Kohn-Sham (ROKS) formalism or within time-dependent density functional theory (TDDFT). As a test case, we apply this technique to the study of the solvent effects on the ground state and on the first excited singlet state of acetone in water. Our results demonstrate that for this system a purely classical description of the solvent is sufficient, since inclusion of the first solvent shell of 12 water molecules into the quantum system does not show a significant effect on this transition. The excited-state energies calculated with ROKS are red shifted by a constant value compared to the TDDFT results, while the relative variations of the excitation energy for different configurations are in very good agreement. The experimentally observed blue shift of the excitation energy in going from gas phase to condensed phase is well reproduced. Excited-state dynamics carried out with ROKS yield the relaxation of the solute and the rearrangement of the solvent structure on a picosecond timescale. The calculated Stokes shift is in reasonable agreement with experimental data.
Pubmed
Web of science
Création de la notice
30/10/2015 8:59
Dernière modification de la notice
20/08/2019 14:52
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