Statistical adiabatic channel model for termolecular reactions

In this work, we present a statistical adiabatic channel model for termolecular reactions, A + B + C → Products. Our approach relies on hyperspherical coordinates, where the adiabatic channels are readily defined in the hyper-radius after averaging the hyperangular degrees of freedom. In this way, we find a general expression for termolecular rate constants. We focus on ion-neutral association reactions to test our approach’s accuracy and predictive power, finding a good agreement between theory and experiment, especially in those reactions’ temperature dependence.