IMPORTANCE OF DIFFERENT MULTIPOLE INTERACTIONS IN FAST REACTIONS AT LOW-TEMPERATURE

For fast reactions dominated by long-range multipole interactions, the adiabatic capture model has been shown to work well for the calculati on of rate constants. The contributions of different multipole interac tions to the rate constants of fast diatom-diatom reactions at low tem peratures have been studied by employing the rotational adiabatic seco nd-order perturbation theory (RA2PT). It is found that at ultralow tem peratures the weak dipole-induced dipole or quadrupole-quadrupole inte ractions will probably become significant and even tend to dominate th e reaction rate due to the properties of the rotational adiabatic pote ntials. Calculations for the CN(X) + O-2 reaction and the CH(A) + CO q uenching process have been performed to demonstrate this behavior.