Knowledge Bank

Vibrational levels near the dissociation limit of the $A^{3}\Pi $(1) electronic state of $I35$ Cl have been studied using fluorescence excitation techniques. By using a single mode ultra high resolution ring laser and a well collimated molecular beam, the hyperfine structure due to both the Iodine (I = 5/2) and Chlorine (I = 3/2) nuclei have been resolved. Calculation of the high energy vibrational wavefunctions, using a R.K.R level of theory, indicates that a large portion of a vibrational period is spent by the two nuclei at internuclear separations greater than their total van der Waals radii. This observation will be the basis for a discussion of the observed trends in the molecular electronic quadrupole ($eQq0$ and $eQq2$) and magnetic hyperfine (a) constants in terms of the atomic orientations as a function of internuclear separation. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$Work supported by NSF.