Rotational excitation of super( 36)ArH+ by He at low temperature

In this paper, we focus on the determination of the rotational excitation rate coefficients of the first observed molecule containing noble gas super( 36)ArH+ isotope by He. Hence, we present the first potential energy surface (PES) of ArH+ -He van der Waals system. The interaction PES of the ArH+(X super( 1)...)-He( super( 1)S) complex is calculated by the ab initio explicitly correlated coupled cluster with single, double, and perturbative triple excitation (CCSD(T)-F12) method in connection with the augmented correlation consistent triple zeta Gaussian basis (aug-cc-pVTZ). The interaction potential presents two global minima of 708.00 and 172.98 cm super( -1) below the ArH+(X super( 1)...)-He( super( 1)S) dissociation limit. Using the PES obtained, we have computed integral inelastic cross-sections in the close-coupling approach among the first 11 rotational levels of ArH+ for energies up to 2500 cm super( -1). Downward rate coefficients were determined at low temperature (T less than or equal to 300 K). It is expected that the data worked out in this study may be beneficial for further astrophysical investigations as well as laboratory experiments. (ProQuest: ... denotes formulae/symbols omitted.)