view article
Figure 4
Structural assessment of a G-twin boundary. (a), (b) Rendering of |ns·nb| on the side surfaces of the reconstructed silica wall at {211} + 0.5 and {220} + 0.5, respectively, shown within slab regions of thickness 0.2 in units of the relevant d spacings. (c) Sectional pore fractions calculated with the reconstructed silica wall, in which the {211} + 0.5 shows the highest contrast. (d) Scatter plot of elevation angles of the surface normal vectors with respect to {211} planes plotted against the offset values, for the G surface (black) and its CMC companions (red and blue). (e), (f) Twin-boundary sections of polysynthetic G twins constructed as minimal and CMC surfaces, respectively, viewed along a common 〈111〉 direction. Colour maps are overlaid to show the minimal distances in units of the d spacing from the un-twinned G surface as in Fig. 2[link]. Note that the surfaces are smoothened at the twin boundaries, while the modification is stronger than in the case of a D-twin boundary.

IUCrJ
Volume 7| Part 2| March 2020| Pages 228-237
ISSN: 2052-2525
https://doi.org/10.1107/S2052252519017287