Knowledge Bank

In recent measurements of infrared transitions in solid parahydrogen with low ortho impurities, using an internal multireflection $systemh$ for a sample path length of 14 cm, we have detected new weak features in the spectral region $10000-13000cm-1$. Of particular interest here is the second overtone band of solid hydrogen and double transitions of the type $Q2(J\prime )+Q1(J)(J,J\prime =:0,1)$ which will be presented. At 10241.07 $cm-1$ the new single transition $W2(0)$ 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 $Q1(1)+Q1(1)$ 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.