Dr. Ilan Benjamin is supported by a grant from the Theoretical and Computational Chemistry Program to perform theoretical studies of transport, adsorption, and chemical reactions which occur at liquid-vapor interfaces. He is using molecular dynamics simulations to gain insight into the solvation free energy and adsorption which takes place at the water liquid-vapor interface, and the effect which this interface has on the equilibrium constant and free energy of activation for various chemical processes such as isomerization equilibrium, unimolecular decomposition and electron transfer. He is developing new methodologies for performing such simulations which include treating the long range coulombic forces by a combination of Ewald summation and reaction field techniques. %%% One of the most challenging and important problems in chemistry is to understand at the molecular level the effect of the medium on chemical reactions which occur at the interfacial region bewtween different phases. Recent advances in very fast time-resolved spectroscopic techniques are yielding new data on solvent effects on dynamical processes in bulk solution and at interfaces. The theoretical research being performed by Dr. Benjamin employs computer simulations based on molecular models to gain a deeper molecular level understanding of the physical and chemical processes which take place at the liquid-vapor interface.