van der Waals rovibrational states of atom–molecule complexes: Ar–benzene and Ar–tetrazine

Abstract

Using an empirical intermolecular potential, we have calculated the van der Waals modes of the atom–molecule complexes Ar–benzene and Ar–tetrazine. In the lower states the atom appears as being localized on one side of the molecular plane. This spectrum can be interpreted qualitatively in terms of one- or two-dimensional oscillators. However, these a very anharmonic and especially the motions along the molecular plane have large amplitudes. At higher energies the increased density of states will lead to an increased coupling between the modes. Furthermore, we have calculated the rotational constants of the complex, which are found to be a good measure for the quality of the ground state potential.