Knowledge Bank

Carbon dioxide clusters were formed by admitting monomeric $CO2$, diluted in an inert gas, into a large cell cooled to $77K1$. The resulting suspension of clusters, each containing of the order of $102$ molecules, were spectroscopically studied through FTIR techniques. The cluster size is such that the number of molecules in the interior is comparable to the number on the exterior (faces, edges and corners). Spectroscopic features associated with vibrational motions of these interior and exterior molecules are observed. Quantum mechanical and electromagnetic classical descriptions of the experimental results will be presented.