Configurational Entropy and Heat Capacity in Supercooled Liquids

We establish the general relationship between the configurational entropy and heat capacity in a supercooled liquid within the framework of equilibrium statistical mechanics. The relationship shows that the configurational entropy is different from the entropy obtained by the integration of the glass heat capacity. In addition, the difference shows the correlation between the energy and entropy in liquid structures. Applying the general results to a simple model, we demonstrate that the difference can be too large to neglect. We also discuss new experiments using the present results.