The uniform approximation for differential cross-sections in the case of weak but R-dependent interaction between two quasimolecular states with repulsive potential curves is obtained for the first time. The formula covers the cases of widely used constant interaction, parallel potential curves, and potential curves without intersection. The close result for the differential cross-section and the scattering amplitude in the particular case of two Coulomb potential curves is obtained too. The consideration has been based on asymptotic evaluation of multydimensional oscillatory integral, the exponent of which has only two saddle points, so the canonical integral of fold catastrophy can be used. It is shown that the cases of constant interaction and Coulomb curves are very specific ones. The cross-section for them has a very developed oscillatory pattern due to the equal contribution from both saddle points. In general case such contributions are different and the oscillatory pattern is being made dirty. The saddle points may move close to one another but not coalesce. So the standart realization of the rainbow angle as the angle at which the saddle points coalesce is not true.
The quasiclassical analysis of differential inelastic scattering of oriented Ca(4s5p, ^1P_1) atoms on He at the collision energy of 1 eV is made. Inelastic channels correspond to spin-changing events populating different Zeeman sublevels of three fine-structure states of Ca(4s5p, ^3P_J), J=0,1,2. The magnitude of the right-left scattering asymmetry in the helicopter plane is shown to depend on the locking dynamics. Predicted large right- -left scattering asymmetry suggested that it can be measured experimentally.
The Hg(6^1,3P_J) + H_2,D_2 potential energy surfaces, dipole moments, and collision-induced radiation of the Hg(6^3P_2) metastable state have been calculated in the quasistatic approach.
The code has been developed for the computation of spectral line shapes in the case of excited atom-atom or diatomic molecule collisions. The code is based on the fast Fourier transform of phase functions calculated with classical trajectories.
