Spectroscopic observation of bound ungerade ion-pair states in molecular hydrogen

Abstract

Phys. Rev. A 84, 20501 (2011).

Continuity of heavy Rydberg behaviour in the ungerade ion-pair states of H 2

“…Ion-pair vibronic states in H 2 were first observed in a timedomain experiment and named Heavy Rydberg (HR) states by Reinhold and Ubachs [7]. They were also identified in the frequency domain above the n ¼ 3 dissociation threshold by Ubachs and coworkers [8,9] in the gerade manifold and later in the ungerade manifold by McCormack and co-workers [10,11]. Measured energies of vibrational levels below the (1s; 2l) dissociation threshold belonging to the lowest ungerade excited state, the B 1 R þ u state, were recently treated with the HR model, and HR behaviour was found to be continuous from v 0 ¼ 0 up to nearly the (1s; 2l) dissociation limit [12].…”

“…(2), and term energy differences between the experimental values and predicted theoretical values made by Kirrander and Jungen [13]. Originally, these resonances were identified by n à , and not all have been observed experimentally [10]. Here we assign those that were observed to vibrational numbers based on a consecutive node counting of calculated vibrational levels of a model diabatic potential constructed from the relevant potential energy curves in Fig.…”

“…[11]. The third region to the left of the arrow (E b ¼ 3300-6000 cm À1 ) comprises the resonances observed above the (1s; 3l) threshold [10,11] and are listed in Table 1.…”

“…The quantum defect plot shown in Fig. 2 [10] above the ð1s; 3lÞ dissociation limit are listed in Table 1 along with ion-pair vibrational assignments, quantum defects calculated from Eq. (2), and term energy differences between the experimental values and predicted theoretical values made by Kirrander and Jungen [13].…”

“…Here, we extend the HR analysis to lower vibrational levels of the outer well of the B 00 B 1 R þ u state and to ungerade resonances [10,11] observed above the ð1s; 3lÞ dissociation limit (see Fig. 1).…”