ABINIT: a computer code for matter

The PAW (Projector Augmented Wave) method has been implemented in the ABINIT Code that computes electronic structures in atoms. This method relies on the simultaneous use of a set of auxiliary functions (in plane waves) and a sphere around each atom. This method allows the computation of systems including many atoms and gives the expression of energy, forces, stress... in terms of the auxiliary function only. We have generated atomic data for iron at very high pressure (over 200 GPa). We get a bcc-hcp transition around 10 GPa and the magnetic order disappears around 50 GPa. This method has been validated on a series of metals. The development of the PAW method has required a great effort for the massive parallelization of the ABINIT code. (A.C.)