Equation of state and elastic properties of face-centered-cubic Fe–Mg alloy at ultrahigh pressures from first-principles

We have calculated the equation of state and elastic properties of face-centered cubic Fe and Fe-rich Fe–Mg alloy at ultrahigh pressures from first principles using the Exact Muffin-Tin Orbitals method. The results show that adding Mg into Fe influences strongly the equation of state, and cause a large degree of softening of the elastic constants, even at concentrations as small as 1–2 at.%. Moreover, the elastic anisotropy increases, and the effect is higher at higher pressures.