One of the great challenges in understanding the functionality of biological molecules from a microscopic perspective has been the development of a detailed understanding of the relative motion and exchange of energy among the enormous number of degrees of freedom in these systems. The three-dimensional structures of these systems have evolved to direct energy into highly specific motions, which are an integral part of the functionality of the molecule. The binding of small molecules at receptor sites can induce large amplitude motions of several angstroms that must be correlated through hundreds to thousands of atoms. The R --> T structure transition of hemoglobin, which controls the binding and release of oxygen, is the hallmark example of these site-directed motions (1-3).