15min:

JASON O. CLEVENGER, NICOLE A. HARRIS AND ROBERT W. FIELD, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139; JIAN LI, Department of Chemistry, Tsinghua University, Beijing, China 100084.

This talk summarizes experimental results from recent ion-dip spectroscopy studies of CaCl as well as previously unpublished optical-optical-double-resonance work with specific regard to predissociation processes of ²⁺ Rydberg states in the low-n* (n* < 7, IP-E ~ 2500\,cm^-1) region. A single repulsive state (assigned as ²⁺) was found to be responsible for all observed predissociations of ²⁺ Rydberg states. The n*-dependent internuclear distances of the intersections between Rydberg and repulsive ²⁺ states were determined through the use of trial-and-error Franck-Condon calculations. Values of the n*-scaled electronic matrix elements governing the Rydberg \leftrightarrow repulsive state interaction were obtained from the measured linewidths (.6 < \Gamma < 1.2 cm^-1) and computed Franck-Condon densities. With the assumption of a one-parameter form for the repulsive curve, E(cm^-1) = \fracC₁₂ R¹²+D_e, where C₁₂ has the units Ź²cm^-1 and D_e = 33171\,cm^-1\,for CaCl, the optimum value of C₁₂ was found to be 2.354 × 10⁸Ź²cm^-1.