The classical model of independent random single deformation faults and twin faulting in face-centered-cubic and hexagonal close packing was revisited. The model was extended to account for the whole range of faulting probabilities. The faulting process resulting in the final stacking sequences was described by several equivalent computational models. The probability sequence tree was established. Random faulting was described as a finite-state automaton machine. An expression giving the percent of hexagonality from the faulting probabilities was derived. The average sizes of the cubic and hexagonal domains were given as a function of single deformation and twinning fault probabilities. An expression for the probability of finding a given sequence within the complete stacking arrangement was also derived. The probability, P0,Δ, of finding two layers of the same type Δ layers apart was derived. It was shown that previous generalizations did not account for all terms in the final probability expressions. The different behaviours of the P0,Δ functions were discussed.

Stacking and Twin Faults in Close-Packed Crystal Structures - Exact Description of Random Faulting Statistics for the Full Range of Faulting Probabilities. E.Estevez-Rams, U.Welzel, M.A.Pentón, E.J.Mittemeijer: Acta Crystallographica A, 2008, 64[5], 537-48