Equation of State for Mg[sub 2]SiO[sub 4] (α-forsterite, β-wadsleyite and γ-ringwoodite): ab-Initio

The compression of Mg2SiO4, (alpha-forsterite, beta-wadsleyite and gamma-ringwoodite) up to 24GPa pressure is analysed with the help of two equation of state : first Birch-Murnaghan and second based on ab-initio pseudopotential approach. It is concluded that the EOS based on ab-initio pseudopotential approach show the systematic compression with increase of pressure in all three phases of Mg2SiO4 as compared to widely used Birch - Murnaghan EOS. The second EOS also yields the value of end point as 1.6 which is in good agreement with the Fermi gas analysis.