HF--HF differential scattering cross sections

Close-coupled scattering calculations have been carried out for collisions between HF molecules in their ground vibrational state at a total energy of 1480 cm-1. State-to-state integral and differential cross sections were determined for transitions j1j2→j'1j'2, which refer to collisions HF(j1)+HF(j2)+ΔE→HF(j'1) +HF(j'2), where ΔE is the energy gap. Particularly large cross sections are obtained for the j j+1→j+1 j transitions, which are both resonant and coupled to first order by the dipole--dipole interaction. The relationship between the calculated cross sections and the results of molecular beam scattering experiments is discussed. Total differential scattering measurements for HF--HF collisions are also reported and compared with the calculated results