Abstract

The recent interstellar detections of ArH+ and HeH+ have increased the interest in noble molecules. In this work, we develop potential energy surfaces (PESs) at a high level of theory for the HeHHe+ + He, ArHAr+ + He, and NeHNe+ + He complexes and study the collision dynamics. A large number of ab initio energies are computed at the coupled-cluster with single, double, and perturbative triple excitations level of theory for the systems. A grid of energies at the complete basis set limit is fitted to an analytical function for each complex. These PESs are then employed in close-coupling calculations at low collision energies. The rotational state-to-state rate coefficients of HeHHe+ by collision He are compared with previous studies, and an excellent agreement is found. Furthermore, the available quenching rate coefficients for ArH+, HeH+, and NeH+, by He, are compared with those computed in this work, and the rotational de-excitations of the diatoms are more efficient than with the triatomic systems. Finally, a set of rate coefficients for ArHAr+ + He, HeHHe+ + He, and NeHNe+ + He at low temperatures is reported.