Quasiclassical trajectory calculations of integral cross sections for highly vibrationally excited Li₂---He, Kr systems

Abstract

On the basis of recently published, bond-distance dependent semiempirical potentials total cross sections have been calculated for Li₂---He and Li₂---Kr collisions as functions of collision energy and initial vibrational state ν₁= 0-20 of the molecule, using either the vibrational adiabatic quantum-mechanical infinite-order-sudden (IOS) approximation or vibration-dependent quasiclassical trajectories (QCT). Via the QCT calculations the experimentally observed non-monotonic change of total cross section with changing initial vibrations state could be reproduced and explained. For Li₂ (ν₁)---He at E_tr=0.08 eV the vibrational and rotational inelastic cross sections at ν₁=20 are significantly larger than for ν₁=0.