Space-group determination by dynamic extinction in convergent-beam electron diffraction

Tables of dynamic extinction lines which occur in convergent-beam electron diffraction patterns (GM lines) are given for all the space groups on the basis of the rules given by Gjønnes & Moodie [Acta Cryst. (1965), 19, 65-67]. It is found that 191 space groups can be identified by GM lines. A convenient experimental method which distinguishes a screw axis and a glide plane is demonstrated. Experimental results are shown in which the GM lines due to a screw axis and those due to a glide plane are separately observed. The GM lines appearing in a symmetrical four-beam pattern are demonstrated.