Structure and dynamics of small van der Waals complexes

Abstract

Microwave spectra and structure of an isoxazole-CO Van der Waals complex J. Chem. Phys. 109, 5383 (1998) Abstract. We illustrate computational aspects of the calculation of the potential energy surfaces of small (up to five atoms) van der Waals complexes with high-level quantum chemistry techniques such as the CCSD(T) method with extended basis sets. We discuss the compromise between the required accuracy and the computational time. Further, we show how these potential energy surfaces can be fitted and used in dynamical calculations such as non-reactive inelastic scattering.

Scattering of NH3 and ND3 with rare gas atoms at low collision energy

“…Calculations for NH 3 -Ne,-Kr, and -Xe have also been performed with various ab initio methods. 16,18,32,[34][35][36] However, these calculations have been restricted to the region close to the van der Waals minimum, and no complete PESs, including the long-range part of the potential, are available. This will limit the accuracy in calculations of scattering cross sections at low energies.…”

“…PESs for the interaction of NH 3 with helium 25 and argon 33 that include a dependence on the inversion coordinate of NH 3 have recently been reported. While a few ab initio studies have been performed on the interaction of ammonia with the other rare gases, 16,18,32,34,35 they did not include a description of the long-range potential that is required for low-energy scattering.…”