This Demonstration enables the calculation of several elastic properties of Si, Ge, and diamond (C) crystals. First, you choose the material and the crystal size. You can then plot Young's modulus, the Poisson ratio, and the shear modulus. You can evaluate the crystal deformation along any crystallographic direction by setting one or two of the perpendicular applied momenta. Finally, you can calculate the effects of miscut and misflat defects.
You can select the material, that is, silicon, germanium, or diamond. Also, you can determine the crystallographic orientation of the crystal plate, in terms of its Miller indices. The last control selects a plot, either Young's modulus, the in-plane and out-of-plane Poisson ratio, or the in-plane and out-of-plane shear modulus.
crystal size length along…
You can set the crystal size. The unit of measure is millimeters.
misflat and miscut effects
By checking the box, you can evaluate the effects of miscut and misflat angles on the elastic properties of the crystal. You can set the two angles. The real orientation of the plane appears in red in the drawing of the crystal.
calculating the crystal deformation
You can calculate the radius of curvature along any crystallographic direction. You can set one or two couples of momenta (or torques). Each momentum couple is applied at the two edges of the crystal along the selected direction. You can evaluate the obtained curvature by selecting a principal orientation or any other crystallographic orientation by rotations about the or axis. Finally, you can see the deformation of the crystal in 3D or 2D. You can select the three principal crystallographic orientations.
 R. Camattari, L. Lanzoni, V. Bellucci, and V. Guidi, "Computer Program for Calculation of Elastic Properties in Silicon and Germanium Crystals" (2015). Journal of Applied Crystallography,48, 10.1107/S1600576715005087.