THE ANISOTROPIC POTENTIAL-ENERGY SURFACES OF H-2,N-2, AND AR WITH C2H2 FROM TOTAL DIFFERENTIAL SCATTERING EXPERIMENTS

The total differential scattering cross sections for H-2, N-2, and Ar with C2H2 were measured on an in-plane crossed molecular beam apparatu s at collision energies of 1051, 1056, and 929 K, respectively. Well r esolved rainbow oscillations for N-2 and Ar, and diffraction oscillati ons for H-2, showed two interference effects. Effective spherical and anisotropic potentials were obtained from analysis using single channe l and infinite-order-sudden (IOS) methods, based on the semiclassical Jeffreys-Wentzel-Kramers-Brillouin (JWKB) approximation. The damping o f oscillations showed the importance of anisotropy in the pair potenti als. Total differential scattering cross sections calculated using the IOS method were in excellent agreement with the experimental data.