The energetics of various low-energy intrinsic, extrinsic and twin-like stacking fault configurations in the hexagonal close-packed metal were deduced from first-principles calculations. It was found that, to zeroth-order, the ordering of the energies could be understood in terms of the number of face-centered cubic-like planes in the sequence of close-packed planes. But such a simple model failed to reproduce quantitatively the calculated energies of the faults. A model was proposed which was based upon a local bond orientation scheme that reproduced the calculated results and was able to predict accurately the energies of arbitrary stacking sequences. This model required only 2 independent parameters: the energy of the intrinsic stacking fault and the energy difference between hexagonal close-packed and face-centered cubic Mg. Both energy and entropy considerations suggested that isolated intrinsic stacking faults should predominate.

Stacking Faults in Magnesium N.Chetty, M.Weinert: Physical Review B, 1997, 56[17], 10844-51