Full-dimensional, ab initio potential energy and dipole moment surfaces for water.
J Chem Phys
; 131(5): 054511, 2009 Aug 07.
Article
en En
| MEDLINE
| ID: mdl-19673578
ABSTRACT
We report full-dimensional, ab initio potential energy (PES) and dipole moment surfaces (DMS) for water. The PES is a sum of one-, two- and three-body terms. The three-body potential is a fit, reported here, to roughly 30,000 intrinsic three-body energies obtained with second-order Møller-Plesset perturbation theory (MP2) and using the aug-cc-pVTZ basis set (avtz). The one- and two-body potentials are from an ab initio water dimer potential [Shank et al., J. Chem. Phys. 130, 144314 (2009)]. The predictive accuracy of the PES is demonstrated for the water trimer, tetramer, and hexamer by comparing the energies and harmonic frequencies obtained from the PES and new high level ab initio calculations at the respective global minima. The DMS is constructed from one- and two-body dipole moments, based on fits to MP2/avtz dipole moments. It is shown to be very accurate for the hexamer by comparison with direct calculations of the hexamer dipole. To illustrate the anharmonic character of the PES one-mode calculations of the 18 monomer fundamentals of the hexamer are reported in normal coordinates.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Teoría Cuántica
/
Agua
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Chem Phys
Año:
2009
Tipo del documento:
Article
País de afiliación:
Estados Unidos