Published in
American Institute of Physics, The Journal of Chemical Physics, 2(132), p. 029902
DOI: 10.1063/1.3291983
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Publisher’s Note: “Ab initio potential energy surfaces for NH(Σ3−)−NH(Σ3−) with analytical long range” [J. Chem. Phys. 131, 224314 (2009)]
,
Gerrit C. Groenenboom ,
Ad van der Avoird,
Piotr S. Żuchowski,
Rafał Podeszwa
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Abstract
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