Nuclear quantum effect on the elasticity of ice VII under pressure: A path-integral molecular dynamics study

We investigate the effect of nuclear quantum effects (NQEs) of hydrogen atoms on the elasticity of ice VII at high pressure and ambient-temperature conditions using path-integral molecular dynamics (PIMD) calculations. We find that the NQEs of hydrogen contribute to the transition of ice VII from a static disordered structure to a dynamically disordered structure at pressures exceeding 40 GPa. This transition is characterized by a nonlinear increase in the elastic constants. A comparison of molecular dynamics, and PIMD calculations shows that NQEs increase the elastic constants of ice by about 20% at 70 GPa and 300 K.