Classical trajectory and adiabatic channel study of the transition from adiabatic to sudden capture dynamics .2. Ion-quadrupole capture

Classical trajectory calculations of ion-permanent quadrupole+induced dipole capture processes are performed over wide ranges of conditions. The results are expressed in two-parametric analytical form, and analyzed with respect to the transition from sudden to adiabatic dynamics, The results are compared with the statistical adiabatic channel model (SACM). For this purpose, adiabatic channel potential curves are expressed in approximate analytical form. The agreement between classical trajectory and SACM results is excellent in the range of adiabatic quasiclassical motion of the collision partners. Analytical expressions can well describe the temperature variation of the capture rate constant in the transition range between the quantum and classical limits. (C) 1996 American Institute of Physics.