Hindered rotation of water molecule in van der Waals complex

Abstract

Abstract. The influence of water molecule symmetry on hindered rotation has been investigated for H20-He,HzO(D20)-C02 systems, where CO2 molecule is treated as an atom. A strong coupling model has been used for calculating the energy spectra. The eigenfunctions of Morse oscillator and asymmetric top have been used as a basis set. The results show that experimentally observed effect of spin-selective water vapour codensation may be explained by the differences between binding energies of para-and orthomodifications for H20(DzO) molecules.PACS: 34.50.I This is precisely the reason for unequilibrium spinmodification distribution of H2 (D2) molecules in free jet expansion [6,7]. From this viewpoint it is interesting to understand why CO2-HzO (D20) dimers are formed mainly with that water molecule modification which contains ground rotational state (for H20 this is the para-and for D20 this is the orthomodification) [8,9]. This property of water molecules manifests itself not only under heterogeneous condensation [8,9] but under adsorbtion as well [10,11].It is the aim of this work to explore an effect of water molecule symmetry on hindered rotation in atom-molecule van der Waal complex.