Lecture
This lecture introduces the concept of symmetry in materials science, focusing on the indistinguishability of elements in crystals and the operations that leave a structure unchanged. It covers symmetry groups, rotation axes, reflection planes, and glide planes. The lecture also discusses crystal classes, space groups, and the generation of point groups. Additionally, it explains the compatibility of symmetry elements with translations, crystal systems, and the seven crystallographic systems. The presentation concludes with a detailed explanation of the Bravais lattice system and the different crystal structures found in nature.