A COMPUTER-SIMULATION APPROACH FOR THE CALCULATION OF DIFFUSE INTENSITY DISTRIBUTIONS FROM CRYSTALS UNDERGOING THE 2H TO 6H TRANSFORMATION BY LAYER DISPLACEMENT MECHANISM

Limitations of the Markovian chain approach for the calculation of dif fuse intensity distributions from crystals undergoing the 2H to 6H tra nsformation by non-random insertion of layer displacement faults are p ointed out. A computer simulation approach for the numerical computati on of the diffuse intensity disributions in such situations is present ed. The numerically computed intensity distributions along diffuse str eaks, obtained by taking Fourier transforms of the pair correlations d etermined from simulated configuration corresponding to the intermedia te states of transformation, show marked departures from those obtaine d analytically using the Markovian chain approach. Explanations for th is discrepancy are advanced.