Post-oxide phases of forsterite and enstatite

TLDR: In this article, the lattice parameters for the perovskite phase of MgSiO3 are ao = 4.790 ± 0.002, bo = 4,943 ± 0.,002, and co = 6.897 ± 0,003 A with Z= 4.083 g/cm³, or 2.8% denser than its isochemical mixed oxides with rocksalt and rutile structures.

Abstract: Both forsterite (Mg2SiO4) and enstatite (MgSiO3) enter a post-oxide phase characterized by the orthorhombic perovskite structure when subjected to high pressure and temperature in the diamond-anvil press coupled with laser heating. The lattice parameters for the perovskite phase of MgSiO3 are ao = 4.790 ± 0.002, bo = 4.943 ± 0.002, and co = 6.897 ± 0.003 A with Z = 4. The calculated density of MgSiO3 (perovskite) is thus 4.083 g/cm³, or 2.8% denser than its isochemical mixed oxides with rocksalt and rutile structures. The density of a mixture of MgSiO3 (perovskite) plus MgO (periclase) is 1.9% greater than that of the mixed oxides with the forsterite stoichiometry.