Dr. Thirumalai has been selected as a Presidential Young Investigator for the period 1987-1992. Although he is a relatively young scientist, the research completed during his graduate and postdoctoral years provides an excellent backgroung in mathematical physics, chemistry and quantum mechanics. It is expected that Dr. Thirumalai will establish a major theoretical research program in the area of simulating dynamic properties of materials. In addition, the research to be carried out will focus on other problems of importance to contemporary chemistry such as (1) understanding specific structural transitions in molecules such as DNA and (2) understanding the dynamics of supercooled liquids and glasses.