Logo of Phonon Mg_2SiO_4


P.Piekarz, P.T.Jochym, K.Parlinski and J.Lazewski,
High-pressure and thermal properties of gamma-Mg_2SiO_4 from first-principles calculations
J.Chem.Phys. 117, 3340 (2002).

Crystal: Magnesium orthosilicate, Gamma spinel, Mg_2SiO_4
Software: Ab initio VASP ver. 4.3.3.
Space group: cubic, Fd-3m (Z=1)
Lattice constants: a=8.1385 angst.
Supercell: 1x1x1.
Pseudopotentials: ultrasoft of Vanderbilt.
k-points: 2x2x2. phase transition.

Free energy at different lattice constants for number of temperature calculated from phonon density of states:

Free energy of Mg_2SiO_4

Thermal volume expansion as a function of temperature compared with experimental data [1].

Thermal expansion of Mg_2SiO_4
[1] I.Suzuki, E.Ohtani and M.Kumazawa, J.Phys.Earth 27, 53 (1979).