Modified Molecular Model for the Description of Condensed Phases of Heavy Water

Using the lattice dynamics method, a simple three-point model of heavy water has been proposed by optimizing thermal expansion and the melting temperature of deuterated hexagonal ice I-h to the experimental values through the parameters of the Lennard-Jones and Coulomb potentials between sites with fixed charges, which describe the interactions between water molecules. The lattice dynamics method includes the energy of zero-point vibrations, which allows more accurate construction of thermodynamic functions. The density of vibrational states, temperature dependence of the linear sizes of the unit cell, and the melting temperature of ice I-h at various concentrations of the D2O molecules have been calculated.

Automated summary

In this study, a simple three-point model for heavy water was proposed using the lattice dynamics method. The parameters of the Lennard-Jones and Coulomb potentials between sites with fixed charges were optimized to match the experimental values of thermal expansion and melting temperature. The method also considered the energy of zero-point vibrations, resulting in more accurate calculations of thermodynamic functions. The study calculated the density of vibrational states, temperature dependence of the unit cell size, and melting temperature of ice I-h at different concentrations of D2O molecules.