Ab initio calculation of the solid phase diagram of beryllium at low pressure and high temperature

Beryllium is likely to be used as an ablator in laser targets of the National Ignition Facility (NIF). In the framework of the construction of predictive, multi-phase equations of state, we have computed from a completely ab-initio simulation, the equation of state and the moduli of elasticity of beryllium. We have shown that the ionic entropy could stabilize a face centered cubic structure at low pressure and high temperature. (A.C.)