15min:

ROBERT J. LE ROY, Guelph-Waterloo Centre for Graduate Work in Chemistry and Biochemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada; THOMAS D. VARBERG, Department of Chemistry, Macalester College, 1600 Grand Ave., St. Paul, MN 55105, USA.

New measurements of far infrared transitions within the v\!=\!1 levels of the X ^{2 +} state of 6 different isotopomers of CdH and CdD are combined with previous mid-infrared^, and far-infrared data in a combined-isotopomer analysis which yields improved rotational constants, spin-rotation constants and Born-Oppenheimer breakdown (BOB) parameters for this system. Recent work by one of us^c had reported the measurement and analysis of far infrared transitions within the v\!=\!0 level of 12 isotopomers CdH and CdD, but the combined-isotopomer analysis reported there found that the CdH and CdD data appeared to be incompatible unless separate Cd-atom BOB parameters were introduced for the inertial rotation constants of CdH and CdD, and BOB parameters introduced for the spin-rotation constants. The present work shows that taking account of the v--dependence of the mechanical rotationl parameters for v\!=\!0 isotopomers implied by the reduced-mass-scaling of vibrational quantum numbers allows the far infrared data to be accounted for without invoking these two assumptions.