This award supports Professor John R. Sabin of the University of Florida and several of his graduate students to collaborate in theoretical materials research with Professor Jens Oddershede of the Chemistry Department of the Odense University, Denmark. Both research groups are highly productive and recognized for their expertise in quantum chemistry. They share an interest in understanding the physical process of energy deposition in matter by swift, massive particles. The Florida group offers strengths in the theoretical aspects of this question, while the group in Denmark has particular strengths in the experimental and theoretical aspects. They propose a series of theoretical and numerical studies related to molecular stopping in several systems. In particular, they will investigate the moments of oscillator strength distributions in small molecules, and also apply a less rigorous approach to calculate stopping cross sections in larger systems. In both cases, a good deal of experimental data exists that has not been examined for theoretical significance. The interaction of swift, massive particles with matter is a field with implications for such diverse studies as detector design and dosimetry, target design for the light ion beam fusion program, radiation therapy in medicine and ion beam implantation of impurities in solids. The proposed collaborative work will be the first consistent theoretical study of energy deposition processes in molecules.