Extension of ion-neutral reactive collision model DNT+ to polar molecules based on average dipole orientation theory

Abstract

The ion-neutral reactive collision model DNT+, which generates comprehensive ion-neutral collision cross section (CS) data sets for atoms and nonpolar molecules, has been extended to polar molecules. The extension is based on the average dipole orientation (ADO) theory, which adds the dipole moment to Langevin–Hassé CS. Furthermore, the ADO CS for short-range reactive collisions is covered with a rigid core to incorporate long-range elastic and charge-exchange collisions. The modified version of DNT+, i.e., DNT+DM, is applied to gas-phase H2O+–H2O and low-energy CF3+–CO collisions for its validation. The cross sections (CSs) for those collisions using DNT+DM show good agreement with literature data, proving that DNT+DM is valid to some extent. Help with ion swarm analyses and measurements is needed to make the predicted CSs more accurate.