Lecture 5: Structures

What we covered in lecture¶

• Site representation, coordinates, and local structural description.

• Molecule representation using SMILES and graph ideas.

• Unit cells, crystal systems, and Bravais lattice concepts.

• Symmetry operations, point groups, and space groups.

• Common structure prototypes and reciprocal-space basics.

• Representation of defects and interfaces.

• File formats and practical structure visualization workflow.

What you should be able to do¶

• Distinguish fractional and Cartesian coordinates and convert between them.

• Explain primitive vs conventional cell in plain language.

• Identify basic prototype families (for example FCC/BCC/HCP, rocksalt, perovskite).

• Read a simple CIF/POSCAR-style structure description and describe key features.

• Use structure terminology correctly: site, symmetry, reciprocal lattice, defect, interface.

Where to review in this book¶

• Structures Overview

• Site

• Molecules

• Unit Cell

• Symmetry

• Structure Prototypes

• Reciprocal Space

• Defect

• Interface

• Structure Formats

• Crystal Structure Notebook

• VESTA Practical