Elastic tensor of the forsterite (Mg2SiO4) under pressure

A complete elastic tensor of the low-pressure structure of the magnesium orthosilicate (Mg2SiO4, forsterite) is determined by an ab initio technique for the pressure range P=0–240 kB. The geologically important quantities: density, sound velocity, Youngʹs modulus, Poissonʹs ratio, crystal anisotropy, are derived from the calculated data. A systematic increase of crystalʹs anisotropy with pressure has been noticed. The results agree well with the available experimental data.