Stacking fault energies in aluminium

The twin, intrinsic and extrinsic stacking fault energies together with the FCC-HCP structural energy difference are calculated for Al by means of the total energy pseudopotential method. The influence of supercell geometry is controlled by extrapolating the calculated data to infinite cell size. All calculations include full interplanar relaxations and the final inter-planar separations are presented and shown to vary systematically for the three stacking faults. The calculated stacking fault energies are shown to be consistent with a simple two-parameter model which describes the effective interactions between atomic planes.