8 GEORGE A. HAGEDORN
This paper represents the culmination of more than a decade of study of molecular sys-
tems. The author would like to thank all the individuals who taught him various techniques,
made numerous crucial comments, and provided encouragement. Particular thanks go to
J. Avron, J.-M. Combes, P. Deift, P. Duclos, M. Klaus, W. Kohler, A. Mead, R. Seiler, B.
Simon, M. Williams, and K. Yajima.