# What is X-ray crystallography?

Oct 4, 2015

X-ray crystallography is basically an analytical technique to study the structures of crystalline atoms or molecules.

The gist of the process is that you fire an X-ray at a small ground-up, closely-packed solid sample. From the way the atom or molecule's crystal structure diffracts the incident X-ray, we can identify what the structure looks like.

The diffraction, called Bragg diffraction, looks roughly like the figure below. The angle $\theta$ is called the Bragg angle and a computer will give a spectrum that shows peaks corresponding to those angles. $d$ is the (non-diagonal) distance between each particle in the crystal structure.