On the occurrence of Zhdanov numbers 1, 2 and 3 in the zigzag sequence of cadmium iodide polytypes

It has been shown that the occurrence of only three Zhdanov numbers, 1, 2 and 3, in the zigzag sequence of cadmium iodide polytypic structures is not accidental but is directly attributable to the fact that the formation of cadmium iodide polytypes takes place through creation and ordering of stacking faults in the basic structure.