A classical trajectory study of collisional energy transfer in thermal unimolecular reactions

Abstract

Classical trajectory calculations have been carried out to study energy transfer in atom–triatom collisions. Collisions between O3 and He, Ar and Xe have been studied at energies corresponding to the temperature range 300–2500 K and between H2O and Ar in the range 2500–10 000 K. The results allow a comparison between the multistep and strong collision models of unimolecular decay. For both O3 and H2O the multistep model gives good agreement with experimental results and the energy transfer characteristics of He, etc. conform to those expected for an inefficient heat-bath gas. Rotational energy transfer is found to be more efficient than vibrational and energy transfer in general is sensitive to the R−6 term in the atom–triatom potential.