Reciprocal Lattice and Diffraction

This lecture covers the concept of reciprocal lattice in 2D systems, focusing on lattice planes, diffraction from a lattice, and diffraction from an atomic structure. It explains how the reciprocal lattice is crucial for understanding scattering and constructive interference, with detailed explanations and demonstrations using supercells and lattice points. The lecture also delves into the diffraction process, emphasizing the conditions for constructive interference and the relationship between wavevectors and lattice vectors. Practical exercises and demonstrations are provided to enhance understanding of diffraction patterns and reciprocal lattice vectors.