Equation of State for Mg_(2)SiO_(4) (alpha-forsterite, beta-wadsleyite and gamma-ringwoodite): ab-Initio

摘要

The compression of Mg_(2)SiO_(4), (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 Mg_(2)SiO_(4) 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.