ISOTOPE SUBSTITUTION IN THE EXPANDED LOCAL MODE APPROACH - XH2-]XHD MOLECULES

In a previous paper (O.N. Ulenikov, R.N. Tolchenov, and Qing-shi Zhu, 1996, Spectrochimica Acta Part A, 52, 1829) we have described the 'exp anded local mode' approach which is a considerable extension of the we ll-known local mode model (M.S. Child and L. Halonen, 1984, Adv. Chem. Phys 57, 1). We report here further extension of the 'expanded local mode' approach and consider, for the case of light atoms, the effects of isotopic substitution on the properties of the Hamiltonian and the spectroscopic parameters. For the XY2 molecules of (C-2v) symmetry, it is shown that by analyzing the properties of the transformation coeff icients, one can obtain relations between the parameters for different isotopomers. (C) 1998 Elsevier Science B.V. All rights reserved.