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A virtual vibrational self-consistent-field method for efficient calculation of molecular vibrational partition functions and thermal effects on molecular properties.

Hansen, Mikkel Bo; Christiansen, Ove; Toffoli, Daniele and Kongsted, Jacob LU (2008) In Journal of Chemical Physics 128(17). p.1-174106
Abstract
A new method is described for the calculation of molecular vibrational partition functions and thermal effects on molecular properties including an explicit account of anharmonicity. The approach is based on the vibrational self-consistent-field method. Partition functions and thermal averages of the energies calculated with the new method are generally in good agreement with the result of more accurate methods. At lower temperatures the method gives in addition good results for thermal averages of dipole moments and polarizabilities. The new method is much more efficient than explicit sum-over-states approaches previously used for calculation of thermal averages. Unlike the standard sum-over-states approach, the newly developed method is... (More)
A new method is described for the calculation of molecular vibrational partition functions and thermal effects on molecular properties including an explicit account of anharmonicity. The approach is based on the vibrational self-consistent-field method. Partition functions and thermal averages of the energies calculated with the new method are generally in good agreement with the result of more accurate methods. At lower temperatures the method gives in addition good results for thermal averages of dipole moments and polarizabilities. The new method is much more efficient than explicit sum-over-states approaches previously used for calculation of thermal averages. Unlike the standard sum-over-states approach, the newly developed method is feasible for larger systems despite the formal exponential increase in the number of states with the size of the system. Thus, it is presently the only practical way for including an explicit treatment of anharmonicity in vibrational wave function based calculations of molecular vibrational partition functions and thermally averaged properties of larger molecules. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
128
issue
17
pages
1 - 174106
publisher
American Institute of Physics
external identifiers
  • wos:000256232400008
  • pmid:18465909
  • scopus:43149112557
ISSN
0021-9606
DOI
10.1063/1.2912184
language
English
LU publication?
yes
id
7a2774ff-7a8c-4c26-9ba9-b6b8fdd36bfa (old id 1154408)
date added to LUP
2008-10-08 12:27:07
date last changed
2017-01-01 04:40:15
@article{7a2774ff-7a8c-4c26-9ba9-b6b8fdd36bfa,
  abstract     = {A new method is described for the calculation of molecular vibrational partition functions and thermal effects on molecular properties including an explicit account of anharmonicity. The approach is based on the vibrational self-consistent-field method. Partition functions and thermal averages of the energies calculated with the new method are generally in good agreement with the result of more accurate methods. At lower temperatures the method gives in addition good results for thermal averages of dipole moments and polarizabilities. The new method is much more efficient than explicit sum-over-states approaches previously used for calculation of thermal averages. Unlike the standard sum-over-states approach, the newly developed method is feasible for larger systems despite the formal exponential increase in the number of states with the size of the system. Thus, it is presently the only practical way for including an explicit treatment of anharmonicity in vibrational wave function based calculations of molecular vibrational partition functions and thermally averaged properties of larger molecules.},
  author       = {Hansen, Mikkel Bo and Christiansen, Ove and Toffoli, Daniele and Kongsted, Jacob},
  issn         = {0021-9606},
  language     = {eng},
  number       = {17},
  pages        = {1--174106},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {A virtual vibrational self-consistent-field method for efficient calculation of molecular vibrational partition functions and thermal effects on molecular properties.},
  url          = {http://dx.doi.org/10.1063/1.2912184},
  volume       = {128},
  year         = {2008},
}