The equation of state for high-pressure phases of ice is key to building models of the cores of icy moons. The vibrational modes play an important role in determining the density at a given pressure and temperature for the crystalline phases; as well, they determine the thermal conductivity. Using DFT techniques, we extract force constants, compute phonon density-of-states, and determine the equation of state to make quantitative predictions in collaboration with experimental measurements at high pressure for Ice VII/VIII.
This work in collaboration with Jackie Li and David Cahill. Computational resources are provided through the Turing cluster at UIUC and the NSF TeraGrid program.