Pyritohedron {104} Pyritohedron {102} Tetartohedron {214}

thingiverse

This text appears to be a comprehensive guide for students to create 3D models of various crystal structures using SolidWorks, a computer-aided design (CAD) software. Here's a breakdown of the content: **Project Overview** The project involves creating a 3D model of a solid by cutting different planes and modeling a specific class of crystals. The student is expected to understand basic concepts such as sketching points, lines, and planes, as well as bodies and features. **Preparation** Before starting the project, students should be familiar with SolidWorks basics, including: * Sketching points, lines, and planes * Understanding bodies and features * Applying the inclusion/exclusion principle **Extension: Exploring Combinations** Once the student has completed the initial project, they can explore different combinations of plane orientations to create various crystal structures. This section encourages students to experiment with changing the coordinates of normal vectors, cutting depths, and symmetry operations. **The Crystal Classes** This section introduces students to five different crystal classes: 1. **Hexoctahedral Class (4/m -3 2/m)**: With four-fold, three-fold, two-fold symmetry, and mirror planes perpendicular to the four-fold and two-fold axes. 2. **Hextetrahedral Class (-4 3 m)**: With four-folds disguised as rotoinverted two-folds. 3. **Gyroidal Class (4 3 2)**: Without mirror planes, this class has a gyroid-like spinning appearance. 4. **Diploidal Class (2/m -3)**: With mirror planes and no four-folds. 5. **Tetartohedral Class (2 3)**: This class has only two-folds and three-folds. **References** The guide provides links to Wikipedia articles on Miller Index, Crystal System, Cubic Crystal System, and the Crystallographic Restriction Theorem. These resources offer additional information on crystallography and symmetry operations. **Rubric & Assessment** A rubric is attached to evaluate student performance based on their ability to create working models of the project and other crystallographic models outlined in the Extension section. Overall, this guide provides a comprehensive introduction to creating 3D models of crystal structures using SolidWorks, covering both basic concepts and advanced topics such as symmetry operations and crystal classes.