In this project in the Experimental Physical Chemistry program of the Chemistry Division Paul Devlin of Oklahoma State University will use vibrational spectroscopy to characterize molecular behavior at the surface of various water ice forms including cubic ice, amorphous ice, acid hydrates, and clathrate hydrates. One focus of the proposed work is on the behavior of "dangling" hydrogen bonds at the surfaces as well as of various types of adsorbed small molecules. Adsorbates of interest include H2, CO2, SO3, HCl, ethyne, benzene, and CO and N2. The nature of structural defects in ice and their importance in the properties and phase transitions of ice and clathrates will also be investigated. Devlin will collaborate with a theoretician who will simulate his experimental data in order to learn more about the adsorption process. This project entails in part a fundamental laboratory study of processes which take place on ice surfaces, many of which are involved in natural phenomena of considerable current interest. Among these are the environmentally urgent issues of the formation of the ozone hole, acid rain, and smog. In addition, these experiments will help elucidate such areas of astrophysical interest as the mechanism of the formation of molecules in interstellar space and the composition of cometary tails.