Abstract The D 1∏u - X1∑g+system of H2 and D2 shows strong predissociation. High resolution m easurements on the line widths of isolated absorption lines have been carried out, showing the influence of rotation on the predissociation probability of the corresponding rotational states. Their lifetime decreases with increasing rotation of the molecule and with decreasing mass due to the coupling of electronic and rotational motion. Both results are in excellent agreement with theoretical predictions given by Kronig. The shape of the absorption lines broadened by predissociation was found to be typically asymmetric. They are of the Beutler type, well known form the autoionisation of the rare gases.
Pressure Effects of Foreign Gases on the Absorption Lines of Cesium