Water cluster for the simulation of hydration of organic compounds: Applying the DFT method

A model of a D 3 symmetry nanocluster consisting of 36 water molecules is developed. This model makes it possible to perform routine simulations of the hydration of small- to medium-sized organic molecules in the cluster using the density functional method. The hydration energies obtained agree with the available experimental data on the correlation coefficient R ≈ 0.83. The application of this model is considered with the examples of the conformational equilibrium of butane and 1,2-ethylenediamine molecules in vacuo and in an aqueous phase, the proton affinity of methylamine and pyridine, stacking interaction in benzene dimer, and proton transfer in the cluster.