Dissociation energy of the ground state of PCl

Very accurate potential energy curves, dipole moment functions, dissociation energies and spectroscopic constants for the ground state (X 3Σ−) of the PCl molecule are reported with the multireference singles and doubles configuration interaction methodology. The effect of increasing the size of the basis set on the dissociation energy and on spectroscopic constants has been analyzed. The use of the Birge–Sponer extrapolation procedure to calculate the dissociation energy was also tested. Our results suggest that the correct D0 value should be a few kcal/mol larger than 71 kcal/mol.