[Calculation of mobility and entropy of the binding of molecules by crystals].

A simple method for evaluating a range of molecular movements in crystals has been developed. This estimate is needed to calculate the entropy of binding, in particular in protein-ligand complexes. The estimate is based on experimental data concerning the enthalpy of sublimation and saturated vapor pressure obtained for 15 organic crystals with melting temperatures of 25-80°Ð¡. For this set, we calculated the values of the average range and the corresponding average amplitude of molecular movements in crystals that constituted 0.75 ± 0.14 Å and 0.18 ± 0.03 Å, respectively. The entropy of sublimation calculated based on the average range of molecular movements in crystals was well consistent with the experimental data.