Thermal transport in liquid and glassy water computed with normal modes

We compute thermal transport coefficients for glassy and liquid water in terms of the normal modes of the glass. We find the thermal diffusivity at 300 K to be close to the actual value of 15 Å2 ps−1, indicating that this property arises largely from the vibrations of the water network. The computed thermal conductivity is about a factor of 2 smaller than the actual value of 6.1 mW cm−1 K−1 for liquid water at 300 K, due to neglect of the configurational contribution to the heat capacity.