Knowledge Bank

CaOH and CaOD were formed in the gas phase by the reaction of $H2O$ and $D2O$ with Ca vapor entrained in a low pressure flow of argon. A single-mode ring dye laser was scanned through the $\Delta v=0$ bands of the A-X system near 625.0 nm. The excitation spectra of CaOH and CaoD were recorded simultaneously with the excitation spectrum of molecular iodine. By measuring the P-R separation of the photoluminescence, we assigned about 140 individual rotational lines of the CaOH (000)-(000) band and about 40 lines of the CaOD (000)-(000) band. Using the molecular iodine lines as a reference, we determined the wavenumbers of those lines with an uncertainty of $\pm 0.01$ $cm-1$. The spin-orbit parameter $A000$ for CaOH is 65.96(2) $cm-1$. Other detailed results and the molecular parameters determined by a least-squares fit to the observed lines will be presented at the conference. We also observed several lines which we attribute to the $A2\Sigma -X2\pi$ and $A2\Delta -X2\Pi$ vibronic transitions of the $(0110)-(0110)$ bands. From these observations, we tentatively determine that the Renner-Teller splitting of the $A(0110)$ state is 9.74(2) $cm-1$ for CaOH and 4.53(2) $cm-1$ for CaOD.