MANY-BODY EXPANSION OF THE POTENTIAL-ENERGY SURFACE FOR BEHF AND DYNAMIC CALCULATIONS FOR THE REACTION, BE+HF(V,J)-]BEF(V',J')+H

A potential function for BeHF has been derived which fits published ab initio data better than other published potentials. The potential has been used for classical trajectory calculations on Be + HF(v, J) --> BeF(v', J') + H. A reactive cross-section of 1.2 angstrom2 is obtained for a collision energy of 146 kJ mol-1 on HF (0, 0). This cross-section is increased by ca. a factor of three for the (1, 0) state. The reaction is predominantly back-scattered, although ca. 30% of trajectories pass through a deep well for the collinear complex FBeH. Trajectories have also been obtained for a potential based on empirical two-body terms and the ab initio three-body term. However, this has a much deeper potential well and is probably less reliable.