We present a first-principles calculation of the lattice dynamics of Be. The dynamical matrix is set up by evaluating the total electron energy up to third order in the electron-ion pseudopotential. In this way we are able to describe the three-body forces, which are essential for reproducing the experimental data.

• Received 28 September 1973

DOI:https://doi.org/10.1103/PhysRevLett.31.1466