LONG-RANGE FEATURES OF POTENTIAL-ENERGY SURFACES FOR THE INTERACTION OF FLUORINE-ATOMS WITH HCL, HBR, AND HI FROM CROSSED MOLECULAR-BEAM EXPERIMENTS

Both integral and differential cross sections have been measured for scattering of a fluorine atom beam by beams of HCl, HBr, and HI. The collision energies for the integral cross sections range from 5 to 175 meV and the laboratory scattering angles probed in the differential cross sections for thermal beams extend from 1-degrees to 13-degrees. The experimental data are analyzed by using an adiabatic decoupling scheme to determine the long-range features for the entrance valleys of the ground and the two lowest excited potential energy surfaces, including nonadiabatic coupling matrix elements.