Figure 6.

The $B20$ structure of FeSi. The enantiomorphous pair RL and LR is shown with $(u_{\mathrm{Fe}},u_{\mathrm{Si}})=(0.3858,0.094)$ and $(0.6142,0.906)$, respectively. RL implies that Fe atoms are positioned in an R type and Si in an L type structure and the opposite for LR. Both structures are shown for views along the [111] axes and arbitrary axes. Fe (or Si) atoms in the triangles of the [111] view are in the same (111) plane; these planes appear at a distance of $(2-u_i)/\sqrt{3}$ from the origin. Atoms in the center, on the [111] axis, are in a different plane $u_i\sqrt{3}$ away from the origin. See Figure 3 for the positions of the screw axes. Connections between atoms are drawn for better visibility and may not be confused with bonds.