This three-year award for U.S.-France cooperative research in materials theory involves Michael Widom of Carnegie Mellon University and Remy Mosseri of the University of Paris VII. The award provides travel support and living expenses to Dr. Widom and his graduate student. The objective of the research is the study of quasicrystals, which are novel aluminum-based alloys that exhibit quasiperiodic structures. The project addresses problems of counting and dynamics of tilings. The U.S. and French investigators bring to this collaboration complementary expertise in atomic level modeling and theory. The project will advance understanding of the physical and mathematical structure of quasicrystals.