(432g) Rapid Characterization and Validity Quantum Isotope Effect Between Light and Heavy Water through Two-Phase Thermodynamics Model

The quantum isotope effect is important indicated the diverse chemical and physical properties of compounds containing D (Deuterium) or ¹³C (Carbon-13) etc. The accurate calculations of these properties have a great challenge from molecular simulation. In this work we tried to use same force field parameters to describe the light and heavy water in pure liquid and solid phase behaver based upon MD (Molecular Dynamics) simulation. And then their energy, enthalpy, entropy and heat capacity were analyzed through 2PT (Two-Phase Thermodynamics) model, it is well to exhibit the differences of these properties due to influence of quantum isotope effect for light and heavy water. Owing to the one more neutron causing the mass difference of light and heavy water, so the translational, rotational and vibrational velocity DoS (Density of State) of heavy water is shift to lower frequency relative to light water. Finally these quantum corrections calculation based on the velocity DoS are shown exact phase behaver and physical chemistry properties for light and heavy water. The results of 2PT model have more accuracy relative to the results of PIMD (Path Integral Molecular Dynamics) simulation comparing with experiments using same SPCF2 water model. There is another merit for 2PT model that we just consume a small computational time to calculated large number of atoms system. And then it is easy to extending our method to finish any computation of complex system in future works.