C2v top data system (C2v TDS) software for infrared spectrum simulation of XY2Z2 asymmetric molecules: some improvements to the TDS packages

The spherical top data system (STDS) program suite developed in Dijon has been extended with the aim of studying any rovibrational band or polyad of XY2Z2(C2v) asymmetric top molecules. We work in the O(3)⊃Td⊃C2v chain because these species result from the substitution of two ligands of a corresponding “parent” spherical top and thus are relatively close to tetrahedral symmetry. The choice of this group chain has consequences on the method used to specify the input parameters of the programs for Hamiltonian and transition moment model calculations. One example concerning the ground state of the SO2F2 quasi-spherical molecule is presented. As before, this suite consists in a series of FORTRAN programs called by a script. The whole package is freely accessible through ftp (user anonymous) at jupiter.u-bourgogne.fr/dist or through the World Wide Web at http://www.u-bourgogne.fr/LPUB/c2vTDS.html. Further general improvements have been brought about for all the TDS packages (STDS, HTDS, C4vTDS) developed in our group and are briefly discussed in the present paper.