Abstract:

To investigate the influences of temperature on the quantum correction for heat capacity of liquid water, molecular dynamics simulations for liquid water were performed and the spectra of velocity autocorrelation function for the atoms were calculated under different temperatures. The study shows that the quantum correction for heat capacity for the three intramolecular vibration modes keeps almost unchanged while the corrections for rotation and libration modes decrease as temperature increases. Corrections were made for the classical heat capacities calculated as the fluctuations of the temperature during the molecular dynamics simulations for liquid water. The corrected results agree well to those from experiments.

Key words: Heat capacity, Quantum correction, MD simulation, Velocity autocorrelation, Liquid water