Anandh Subramaniam & Kantesh Balani MATERIALS SCIENCE & ENGINEERING Anandh Subramaniam & Kantesh Balani Materials Science and Engineering (MSE) Indian Institute of Technology, Kanpur- 208016 Email: anandh@iitk.ac.in, URL: home.iitk.ac.in/~anandh AN INTRODUCTORY E-BOOK Part of http://home.iitk.ac.in/~anandh/E-book.htm A Learner’s Guide

A note on kind of models used for representation of Crystal Structures Wire Frame model Ball & Stick Model Atoms are reduced to points and the focus is on the cell edges Both atoms & cell edges are in view (but atoms do not touch each other) Cubic void Void Models Space Filling Model Where the void (actually the polyhedron formed by the vertices of the void) is in full view and everything else is hidden away Atoms touch each other. Unit cell edges may not be visible Note: though these are called space filling models in reality they do not fill space [as obvious from the space between the atoms (-the voids)] Video: models for crystal structures