Used in the following papers:

Surface oscillatory thermal expansion: Mg (10-10),
Ismail, E.W. Plummer, M. Lazzeri, and S. de Gironcoli,
Phys. Rev. B 63}, 233401 (2001)

First principles thermoelasticity of MgSiO$_3$-perovskite:
consequences for the inferred properties of the lower mantle,
B.B. Karki, R.M. Wentzcovitch, S. de Gironcoli, and S. Baroni,
Geophys. Res. Lett. 28, 2699 (2001).

High pressure lattice dynamics and thermoelasticity of MgO, 
B.B. Karki, R.M. Wentzcovitch, S. de Gironcoli, and S. Baroni,
Phys. Rev. B 61, 8793 (2000).

Ab initio lattice dynamics of MgSiO_3 perovskite at high pressure,
B.B. Karki, R.M. Wentzcovitch, S. de Gironcoli, and S. Baroni,
Phys. Rev. B 62, 14750 (2000).

Effects of short-range-order on the optical properties of the
Zn_xMg_(1-x)S_ySe_(1-y) quaternary alloy, A.M. Saitta, S. de Gironcoli,
and S. Baroni, Appl. Phys. Lett. 75, 2746 (1999).

First-Principles Determination of Elastic Anisotropy and Wave Velocities
of MgO at Lower Mantle Conditions, B.B. Karki, R.M. Wentzcovitch,
S. de Gironcoli, and S. Baroni, Science 286, 1705 (1999).

Structural and Electronic Properties of a Wide-Gap Quaternary Solid
Solution: (Zn,Mg)(S,Se), A.M. Saitta, S. de Gironcoli, and S. Baroni,
Phys. Rev. Lett. 80, 4939 (1998).