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Analytic cubic and ...
Analytic cubic and quartic force fields using density-functional theory
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Ringholm, M. (författare)
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Jonsson, D. (författare)
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- Bast, Radovan (författare)
- KTH,Teoretisk kemi och biologi,Parallelldatorcentrum, PDC
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Gao, B. (författare)
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Thorvaldsen, A. J. (författare)
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Ekström, U. (författare)
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Helgaker, T. (författare)
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Ruud, K. (författare)
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(creator_code:org_t)
- AIP Publishing, 2014
- 2014
- Engelska.
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 140:3, s. 034103-
- Relaterad länk:
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https://www.duo.uio....
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- We present the first analytic implementation of cubic and quartic force constants at the level of Kohn-Sham density-functional theory. The implementation is based on an open-ended formalism for the evaluation of energy derivatives in an atomic-orbital basis. The implementation relies on the availability of open-ended codes for evaluation of one- and two-electron integrals differentiated with respect to nuclear displacements as well as automatic differentiation of the exchange-correlation kernels. We use generalized second-order vibrational perturbation theory to calculate the fundamental frequencies of methane, ethane, benzene, and aniline, comparing B3LYP, BLYP, and Hartree-Fock results. The Hartree-Fock anharmonic corrections agree well with the B3LYP corrections when calculated at the B3LYP geometry and from B3LYP normal coordinates, suggesting that the inclusion of electron correlation is not essential for the reliable calculation of cubic and quartic force constants.
Ämnesord
- NATURVETENSKAP -- Fysik -- Annan fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Other Physics Topics (hsv//eng)
Nyckelord
- Anharmonic correction
- Automatic differentiations
- Exchange-correlation kernel
- Fundamental frequencies
- Kohn-Sham density-functional theory
- Quartic force constants
- Two-electron integrals
- Vibrational perturbation theory
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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