Dissociation energy of the ground state of PCl

Very accurate potential energy curves, dipole moment functions, dissociatio n energies and spectroscopic constants for the ground state (X(3)Sigma(-)) of the PCl molecule are reported with the multireference singles and double s 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 c alculate the dissociation energy was also tested. Our results suggest that the correct D-o value should be a few kcal/mol larger than 71 kcal/mol. (C) 1999 Elsevier Science B.V. All rights reserved.