Used in the following papers:

A first principles study of the thermal expansion of Be (10-10), 
M. Lazzeri, and S. de Gironcoli, Phys. Rev. B 65, 245402 (2002).

Ab-initio study of Be (10-10) surface dynamical properties, 
M. Lazzeri, and S. de Gironcoli, Surf. Sci. 454-456, 442 (2000).

Ab-initio dynamical properties of  Be (0001) surface, 
M. Lazzeri, and S. de Gironcoli, Surf. Sci. 402-404, 715 (1998).

Ab-Initio Study of Be (0001) Surface Thermal Expansion,
M. Lazzeri, and S. de Gironcoli, Phys. Rev. Lett. 81,  2096 (1998).