Ion-pair and Rydberg states of ArH

Abstract

Ab initio MRD-CI calculations have been carried out on electronic states of ArH at intermediate and large internuclear distances, where ion-pair, Ar+H-, states as well as excited Ar(3P, 1P) states interact with the states involving excited H limits. The results show that charge transfer character contributes to the lowest three 2 Sigma + states and two 2 Pi states for internuclear distances from 4.0 to 10.0 a0. The ion-pair states are found to have minima at 4.5 a0 and at 6.5 a0 where they correspond to the lowest 2 Pi and the first excited 2 Sigma + states of ArH. In addition to the above, potential energy curves have been produced for a large number of Rydberg states of ArH, correlating with dissociation limits up to H n=4.