LASER SPECTROSCOPY OF THE CAOH A 2-PI-CHI-2-SIGMA+ (020)-(000) BAND - DEPERTURBATION OF THE FERMI RESONANCE, RENNER-TELLER, AND SPIN ORBIT INTERACTIONS

The A 2PI-X 2SIGMA+ (020)-(000) band of CaOH has been observed using cw dye laser excitation, and rotationally analyzed. The measured line positions, in combination with data obtained in our laboratory for the A 2PI-X 2SIGMA+ (100)-(000) band, have been employed in a global deperturbation of the A (100) 2PI and A(020)kappa 2PI and mu 2PI vibronic states that simultaneously takes account of Fermi resonance, the Renner-Teller effect, and spin-orbit coupling. All the measured line positions are reproduced to within the measurement accuracy of 0.005 cm-1. The Renner-Teller and Fermi resonance parameters in the CaOH A 2PI state have been determined: epsilonomega2 = -36.569 19(97) cm-1 and W1 = 10.300 58(54) cm-1.