OBSERVATION OF NEW INFRARED TRANSITIONS IN SOLID PARAHYDROGEN

$^{a}$R. A. Steinhoff, B. P. Winnewisser and M. Winnewisser, Phys. Rev. Lett. 73, 2833-2836 (1994).Author Institution: Physikalisch-Chemisches Institut, Justus-Liebig-UniversitatIn recent measurements of infrared transitions in solid parahydrogen with low ortho impurities, using an internal multireflection $system^{h}$ for a sample path length of 14 cm, we have detected new weak features in the spectral region $10000-13000 cm^{-1}$. Of particular interest here is the second overtone band of solid hydrogen and double transitions of the type $Q_{2}(J^{\prime}) + Q_{1}(J)(J,J^{\prime} =: 0,1)$ which will be presented. At 10241.07 $cm^{-1}$ the new single transition $W_{2}(0)$ could be observed. We will also present further results of the analysis of our measurements in the first overtone region, especially a theoretical explanation of the intensities in the fine structure of the $Q_{1}(1) + Q_{1}(1)$ double transition. The absorption spectrum in the mid-infrared region (700-2000 $cm^{-1}$) is currently under investigation, and new information in this region will also be presented