CW ALL-OPTICAL TRIPLE-RESONANCE SPECTROSCOPY OF K2 - DEPERTURBATION ANALYSIS OF THE A1-SIGMA-U+ (UPSILON LESS-THAN-OR-EQUAL-TO 12) AND B3-PI-U (13 LESS-THAN-OR-EQUAL-TO UPSILON LESS-THAN-OR-EQUAL-TO 24) STATES

The lowest vibrational levels v = 0 to 12 of the A1Σu+ state of K2, which are perturbed by the b3Πu state (13 ≤ v ≤ 24), were reexamined using all-optical triple-resonance (AOTR) spectroscopy. The experimental data were fitted by a nonlinear least-squares fit program to obtain deperturbed molecular constants for both the A1Σu+ and b3Πu states. Improved Dunham coefficients of the A1Σu+ state in the range 0 ≤ v ≤ 62 are determined from the deperturbed Tv and Bv values including the v ≤ 12 region of this work, the v = 12-18 region in the work of Ross et al. [J. Phys. B.20, 6225-6231 (1987)], and the v = 21-62 region in the work of Lyyra et al. [J. Chem. Phys.92, 43-50 (1990)]. The electronic matrix element for the A1Σu+ ∼ b3Πu interaction is Hel = 18.64(9) cm-1, in good agreement with the value of 18.4 (2) cm-1 found by Ross et al. © 1992.