Ab initio potential energy surfaces for NH-NH with analytical long range
| Autor: | Janssen, Liesbeth M. C., Groenenboom, Gerrit C., van der Avoird, Ad, Żuchowski, Piotr S., Podeszwa, Rafal |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | J. Chem. Phys., 131, 224314 (2009) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1063/1.3268920 |
| Popis: | We present four-dimensional ab initio potential energy surfaces for the three spin states of the NH-NH complex. The potentials are partially based on the work of Dhont et al. [J. Chem. Phys. 123, 184302 (2005)]. The surface for the quintet state is obtained at the RCCSD(T)/aug-cc-pVTZ level of theory and the energy diferences with the singlet and triplet states are calculated at the CASPTn/aug-cc-pVTZ (n = 2; 3) level of theory. The ab initio potentials are fitted to coupled spherical harmonics in the angular coordinates, and the long range is further expanded as a power series in 1/R. The RCCSD(T) potential is corrected for a size-consistency error prior to fitting. The long-range coeficients obtained from the fit are found to be in good agreement with perturbation theory calculations. Comment: submitted to JCP, supporting information available from authors on request |
| Databáze: | arXiv |
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