Note on the physical basis of spatially resolved thermodynamic functions

The spatial resolution of extensive thermodynamic functions is discussed. A physical definition the based on a analogy partial molar quantities advocated, which shown to be consistent with how hydration energies are typically spatially resolved in molecular simulation literature. It then that, provided solvent not at phase transition, entropy function calculated by first-order grid inhomogeneous solvation theory [Nguyen CN, Young TK, Gilson MK. Grid theory: structure and thermodynamics miniature receptor cucurbit [7] uril. J Chem Phys. 2012;137(4):044101] satisfies rigorously, whereas that cell [Gerogiokas G, Calabro Henchman RH, et al. Prediction small molecule theory. Theory Comput. 2014;10(1):35–48] most likely does not. Moreover, for an ideal gas external field, former latter Finally, proposed case we derive approximate expression contribution free energy limit infinite dilution from variation density around solute.