COMPUTATION OF THE PID FROM A STACKING SEQUENCE CANDIDATE

Step 1. Conversion from RTW symbols into provisional OD or Z symbols in the homo-octahedral approximation, by simply looking for Zv = 0 or [i.e. c = (0, 

Step 3. Expression of the stacking operators Xj, which give the displacement between the j- )-th and the j-th TS layers, as a function of OD or Z symbols and calculation of TS symbols. The relation of the stacking operators Xj with OD or Z symbols 

Subclass must be taken into account. OD and Z symbols for non-orthogonal polytypes always correspond to (1/3, Q) (fflass a) or (0, 1/3) Class b). The PID is most conveniently expressed in the axial setting, which corresponds to c = (1/3, 0) or 

Step 4. Computation of PID (S ) as a function of the (a, b) components of TS symbols. The components of they-th TS layer referred to the (a, b) axes are indicated as (Xy, Yy), to distinguish from the components in A, A2) axes, which were labeled (AXy, AYy) (Eqn. (22) and (24)). (Xy, Yy) are equal to the sum of the (Xr, x ) components of the stacking operators from the first toy-th stacking operators. However, necause the c axis of the axial setting is displaced -1/3 - (where n is the Series) along a or b 

Finally, in Class b the axes exchange a b expresses PID in the F axial setting. 

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