Trajectory calculations of high temperature and kinetic energy dependent ion–polar molecule collision rate constants

Abstract

The trajectory method is used to calculate high temperature and kinetic energy dependent ion–polar molecule collision rate constants. A new ion–polar molecule interaction potential energy surface is derived which takes into account the average hard sphere diameter of the colliding partners and the dimensions of the permanent dipole and the induced dipole vectors. A model system, H+3+NH3 is chosen for the calculation. The calculated results show that at low temperatures and kinetic energies, the effects of the size of the ion–molecule partners and the dimensions of the dipole vectors on the collision rate constant are small. At high temperature and high relative kinetic energies, however, these effects are significant. The calculated results are in good agreement with existing experimental kinetic energy dependent reaction rate constants.