The role of asymptotic vibrational states in

Calculations are discussed which characterize all the vibrational bound states of the and D 2 H + molecular ions using a realistic ab initio potential energy surface. Graphical analysis and calculation of rotational constants show that both ions support a series of atom–diatom-like long-range states: asymptotic vibrational states. The role of these states in the system and other molecules is discussed. The vibrational calculations are extended above dissociation where the resulting (Feshbach) resonances are shown to be too short-lived to be of importance for the photodissociation spectrum.

Photodissociation Spectroscopy of (C6H6)2+

The photodissociation spectrum of (C6H6)2+ is obtained from the yields of fragment C6H6+ ion as a function of photodissociation wavelength in the 400–1400 nm region. Two bands at 440 and 580 nm are attributed to the C ← X and the B ← X local excitation (LE) bands, respectively. Both the most intense band at 920 nm and relatively weak one at 1160 nm are assigned to charge resonance (CR) bands. The red-shift of the B ← X band from that of C6H6+ and the cross sections at the CR bands much larger than those at the LE bands are consistent with a sandwich structure for (C6H6)2+. The appearance of the two CR bands is explained on the basis of displaced sandwich structures for (C6H6)2+.