Uses of systems with degrees of freedom poised between fully quantum and fully classical states

A method of drug discovery, comprising:

• selecting a biological target;
• screening a library of candidate molecules by conducting an in vitro binding assay to identify a first subset of candidate molecules that bind to the biological target;
• determining the energy level spacing distribution of a quantum degree of freedom in each of the candidate molecules in the first subset by evaluating their mean energy level spacing as a function of energy;
• conducting an in vitro or in vivo assay for biological activity on each of the candidate molecules in the first subset;
• correlating the energy level spacing distribution with activity determined from the in vitro or in vivo assay;
• determining the energy level spacing distributions of a quantum degree of freedom in a new set of candidate molecules by evaluating their mean energy level spacing as a function of energy;
• comparing the energy level spacing distributions of the new set of candidate molecules with energy level spacing distributions that correlate with biological activity to determine their degree of similarity;
• and
• selecting as drug candidates from the new set of candidate molecules for drug development or medicinal chemistry those molecules whose energy level spacing distributions exhibit a pre-determined level of similarity to the energy level spacing distributions that correlate with biological activity, wherein the selected drug candidates are more likely to contain biologically active molecules than non-selected molecules from the new set of candidate molecules.