Rotational excitation with pointwise vibrational wave functions

Abstract

Finite element methods, particularly the discrete variable representation (DVR), have proved very successful for calculations on highly excited vibrational states. A procedure is given for calculating the corresponding rotationally excited states for triatomic molecules represented by either scattering (Jacobi) or Radau coordinates. By exploiting the quadrature approximation and the transformation between DVR and basis function representations, this procedure greatly simplifies the calculation of the Coriolis coupling matrix elements. The computational expense of the calculation is thus dominated by that of the underlying vibrational problem. Test results are presented for the benchmark molecules H2S, H2O and H3+.