Large scale vibrational Hamiltonian calculations on thiophosgene

The vibrational spectrum and ground electronic state potential energy surface (PES) of thiophosgene (CSCl2) have been studied quantum mechanically using a completely symmetrized Hamiltonian formalism and vibrational basis set, including all six molecular vibrational modes in the calculations. The calculated vibrational frequencies have been compared to the experimentally measured data by other authors. From a good fit achieved between the theoretical and experimental frequencies up to considerably high excess vibrational energies, the harmonic and some anharmonic (cubic and quartic) force constants of the molecular PES have been reliably determined.