1. Software and System Division; National Institute of Standards and Technology; Gaithersburg Maryland 20899
2. Institute for Advanced Computer Studies; University of Maryland; College Park Maryland 20742
3. Mathematics and Computer Science; Goucher College; Baltimore Maryland 21204
4. Laboratory of Neurochemistry, NINDS; National Institutes of Health; Bethesda Maryland 20892
5. Division of Computational Bioscience; Center for Molecular Modeling, CIT, National Institutes of Health; Bethesda Maryland 20892