Tutorials
This is a list of topics of interest to those studying crystallography, and in particular to those interested in experimental and computational studies of crystal structures.
If you have any questions, or a topic you would like addressed, please send us an email.
1 | Chiral Space Groups
Many crystals, particularly organics, are chiral pairs -- each has a mirror image structure with exactly the same properties as its twin. Why does this happen? How often does happen? What symmetries allow this? Who is the heck is Sohncke?
Here we explore the world of chiral systems and the space groups that allow them.
Date: 29th November 2024 | Presenter: Michael Mehl | Editor: Hagen Eckert
2 | Distribution of Structures in Space Groups
Crystals structures can be cubic, hexagonal, tetragonal, or have less regular shapes. But how many crystals of each type are there? If you pick up a random crystal, is it likely to have a cubic structure? Hexagonal? Does it depend on the sample being organic or not? We look at how many (and what kind) of crystals are in every symmetry and space group.
Date: 8th March 2025 | Presenter: Michael Mehl | Editor: Hagen Eckert
3 | The AFLOW Prototype Label
Every crystal structure in this Encyclopedia has what is known as an AFLOW Prototype Label which has information about its crystal structure and stoichiometry. So what does something like AB4C_tP12_127_a_eg_c-001 mean? We'll reveal the secrets of the Prototype Label, how you can construct one, and how (and when) to use it.
Date: 7th March 2025 | Presenter: Michael Mehl | Editor: Hagen Eckert
4a | Crystallography and Computational Quantum Mechanics | Lattices and Basis
Every periodic crystal is defined by its lattice — how it repeats in space, and its basis — how the atoms are distributed in the lattice. This introduction to crystallography talks describes the possible types the lattice and basis, as well as the notation we use to describe them in the Encyclopedia and these tutorials.
Date: 30th October 2025 | Presenter: Michael Mehl | Editor: Hagen Eckert