 | Acta Crystallographica Section B Acta Crystallographica Section B STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS |
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![[Figure 12]](wf5108fig12mag.jpg)
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Figure 12
Schematic representation of the single-crystal diffraction pattern of the twinned structure of the MDO1 (4A) polytype of kermesite, Kupčík's axial setting; the c* vector is perpendicular to the projection plane. Large full circles for k = 2n (and also h = 2n, l = 2n) represent the family reflections with monoclinic symmetry. Small black and red circles for k = 2n + 1 (and also h = 2n + 1, l = 2n + 1) represent the characteristic (polytype) reflections for the first and second twin domain, respectively. The reciprocal unit cells and indices h, k for the first and second domains are indicated in black and red, respectively. The c* vectors of the first and second domain are oriented to and from the observer, respectively. All present reflections must obey the reflection condition of Kupčík's cell (hkl: h + k = 4n, k + l = 2n, h + l = 2n, h − k + 2l = 4n). |
![[Figure 12]](wf5108fig12.jpg)
| STRUCTURAL SCIENCE CRYSTAL ENGINEERING MATERIALS |
ISSN: 2052-5206
