 | Acta Crystallographica Section B Acta Crystallographica Section B STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS |
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![[Figure 13]](bk5084fig13mag.jpg)
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Figure 13
Schematic depiction of the diffraction pattern of VAR205 with main and satellite reflections and modulation wavevector q = 0.14·a* + 0.38·c*. (a) Neglecting satellite reflections (light grey) results in a three-dimensional unit cell of a = 6.4, b = 6.5, c = 22.7 Å (average structure). (b) Using all reflections equivalently results in a three-dimensional unit cell a′ = 7·a = 44.8 Å, b′ = b = 6.5 Å and c′ = 5·c = 113.5 Å (supercell). The volume of this superstructure unit cell is 35 times that of the unit cell of the average structure. Once the q vector is known the unit cell can also be derived by looking for the smallest integer numbers with which the components of the q vector (approximated by rational numbers, here: 2/5 and 1/7) have to be multiplied to reach a lattice point of the main reflections (c). Those integers have to be applied to the cell parameters of the small unit cell from (a) to give the big unit cell from (b). |
![[Figure 13]](bk5084fig13.jpg)
| STRUCTURAL SCIENCE CRYSTAL ENGINEERING MATERIALS |
ISSN: 2052-5206
