Between the dreier ring layers of Ba Eu Al Si

6 shows examples of stacking variations with the punctuated equilibrium slabs of model 1, only with different orientations of dreier-ring layers and the slab layers. Wide varieties of stacking sequences could be possible, which would cause diffuse lines and streaks in the ED and XRD photographs. These faults could not be distinguished from the c-axis direction, as shown in the projection of the average structure on to the b–c plane 'CHIR-98014' ( Fig.