Knowledge Bank

The a $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\pi -X1\Sigma +$ system of AlBr has been recorded in the region $4040-4370\backslash AA$ as part of our efforts to extend such observations to higher energies. The spectrum is in good agreement with that reported by $Sharma1$ and Lakshminaragana and $Haranath2$ except our resolution is considerably better than that used by Lakshminaragana and Haranath for their rotational analyses. The present analysis of the 0-0 band takes advantage of the known microwave transitions of AlBr by Wyse and $Gordy3$, and it includes extensive data for both $Al79Br$ and $Al81Br$ which are present in approximately equal amounts. Rotational constants for both states, including those of spin orbit splitting and lambda-type doubling for the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\pi$ state, were determined and then merged with those obtained by fitting the microwave $transitions.3$ A preliminary set of constants (in $cm-1$) for the a $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\pi$ state of $Al81Br$ is given below; $ \begin{array}{lll} \upsilon_{00} = 23 794.60 & A = 131.20 & A_{0} = - 1.47 \times 10^{-4}\ B = 0.163621 && D = 1.02\times 10^{-7} \end{array}$ A similar approach is underway for the analysis of transitions involving v = 1 and v = 2 of the a $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\pi$ state.