What is X-ray crystallography?

X-ray crystallography is a technique used to determine the atomic and molecular structure of a crystal. In this technique, a beam of X-rays strikes a crystal and diffracts into many specific directions. By measuring the angles and intensities of these diffracted beams, a three-dimensional picture of the density of electrons within the crystal can be produced. From this electron density, the positions of the atoms in the crystal can be determined, as well as their chemical bonds, disorders, and other attributes. It is widely used in chemistry, materials science, and biology to identify the structure of a wide range of materials, including proteins, DNA, and pharmaceuticals.