The F+D2 and F+HD reactions were investigated in a high resolution crossed molecular beams experiment at several collision energies. The DF product from both reactions was predominantly backward scattered although some forward scattered DF(v=4) was observed at the highest energy studied. The HF angular distributions from F+HD were quite different, showing considerable forward scattered (v=3) and no other identifiable structure. These results disagree with classical trajectory studies, which predict only small variations in the product angular distributions among F+H2 and its isotopic variants. They agree, however, with the predicted dependence of dynamical resonance effects on isotopic substitution. The results therefore support the conclusions drawn in the previous paper regarding the role of dynamical resonances in the F+H2 reaction.

Accurate potentials for ground state krypton-krypton and xenon-xenon interactions are derived using a wide range of experimental evidence including second virial coefficients, gas transport properties, solid state data, known long-range interactions, spectroscopic information on dimers, and new measurements of differential scattering cross sections. In calculating solid-state properties account is taken of long-range many-body interactions. The use of the potentials permits a critical intercomparison of various kinds of experimental data. A ``corresponding states'' comparison of the shapes of the potentials for different inert gas pairs is given. It is concluded that contributions of overlap-dependent many-body interactions to condensed-phase properties of argon, krypton, and xenon are very small.

High-resolution differential cross sections for elastic scattering extending to wide scattering angles for He–He and Ne–Ne have been measured at two collision energies in the thermal range. The experiments were carried out by crossing two supersonic nozzle atom beams at right angles and detecting the atoms scattered in the plane of the beams with a rotatable electron-bombardment mass-filter universal detector. The results are analyzed to yield information on the interatomic potentials for these systems using a realistic and flexible potential function, and comparison is made with previously proposed potentials. For He2, a somewhat ``harder'' low-energy repulsion than that of most such potentials is inferred, while for Ne2 the potential well depth found is ∼ 30 % larger than earlier estimates and in good agreement with a preliminary spectroscopic finding.

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