Knowledge Bank

At present, there is considerable interest in attempting accurate determination of the anharmonic potential functions of polyatomic molecules because of the availability of electronic computers. The work done on the carbon dioxide and nitrous oxide molecules suggests that it would be worthwhile to investigate a four atomic linear molecule as the next step. The acetylene molecule and its isotopic species offer an excellent possibility. The need for procuring precise internally consistent data necessitated the development of improved techniques of observation, measurement and analysis of the rotational structure of overlapping vibration rotation bands. Several bands of the dideuteroacetylene molecule occurring in the 3-5 micron region were measured, and molecular constants of the levels involved were evaluated. The progress made on the study of the infrared bands of $C2D2$ will be discussed.