DVR1D: programs for mixed pointwise/basis set calculation of ro-vibrational spectra

Abstract

DVR1D calculates vibrational energy levels and wavefunctions for triatomic molecules in either scattering (Jacobi) or Radau coordinates for a given potential. The program uses a discrete variable representation (DVR) for the angular coordinate and a choice of basis functions for the radial coordinates. The program is particularly appropriate for high lying vibrational states. The accompanying program ROTLEV2 is driven by DVR1D and calculates rotationally excited states of AB 2 molecules such as water using Radau coordinates and a “bisector” axis embedding which properly reflects the symmetry of the system. DVR1D can also drive ROTLEVD, DIPOLE and hence SPECTRA from the TRIATOM program suite (Tennyson et al., Comput. Phys. Commun., previous article).