Elastic anisotropy of ε-Fe under conditions at the Earth's inner core

Elastic anisotropies of ε-Fe under conditions at the Earth's inner core are investigated by using the generalized gradient approximation within density functional theory. We find that the elastic anisotropies of ε-Fe are mainly affected by high pressure (330-360 GPa), not by high temperature (3000-6000 K). The anisotropies of the compressional elastic wave (P) and the wave polarized in the basal plane (S2) are slight, with temperature from 3000 to 6000 K. The obtained orientation dependences of acoustic velocities agree well with experiments.