POTENTIAL-ENERGY CURVE AND DISSOCIATION-ENERGY FOR THE SNCL MOLECULE

The potential energy curve for the electronic ground state of the SnCl molecule has been constructed by the Rydberg-Klein-Rees method in the modification by Vanderslice and collaborators. Empirical potential functions, of five parameters by Hulburt and Hirschfelder, of three parameters by Lippincott and collaborators, and that by Szoke and Baitz using the electronegativity are examined for their adequacy to represent the true, curve. The five parameter Hulburt-Hirschfelder function, U(r) = D(e)[(1 - e(-x))2 + c x3e-2x (1 + b x)], was found to be the best fitting function and it was used for the determination of the dissociation energy. The estimated value attained for dissociation energy is 346 +/- 8 kJ mol-1. For this value of dissociation energy, the estimated values for the parameters and expansion coefficients are c = 0.06864, b = -0.363738, a0 = 2.759 . 10(3) m-1, a1 = 2.876 and a2 = 4.013, a0, a1 and a2 being the Dunham's coefficients.