Crystallography

Crystallography is the study of how tiny parts of materials are arranged and what this means for their properties. The word crystallography comes from Ancient Greek words. It helps us learn about materials by looking at their building blocks.

In 2014, the United Nations said that crystallography is very important for the world.

Crystallography looks at many things, such as X-ray crystallography. This science studies how X-rays bounce off materials to show where atoms are. It helps scientists in biology, chemistry, and physics learn new things.

History and timeline

Main articles: Timeline of crystallography and History of crystallography before X-rays

Long ago, scientists studied crystals by measuring the angles between their faces using tools like a goniometer. They used these measurements to learn about the crystal's symmetry.

In the late 1800s, the discovery of X-rays and electrons changed everything. In 1912, Max von Laue did the first X-ray diffraction experiment, and in 1927, electrons were used in diffraction for the first time. These discoveries helped scientists see inside crystals and start the modern field of crystallography. Today, scientists use many tools to study crystals and learn new things.

Methodology

Main articles: X-ray crystallography, Electron diffraction, Neutron crystallography, and NMR crystallography

Crystallography looks at how tiny parts of materials are arranged. It does this by seeing how beams of energy, like X-rays, bounce off the material. These beams can also be electrons or neutrons. Each type of beam shows different details about the material. For example, X-rays show where electrons are, and electrons can make very detailed pictures. These methods help scientists learn about the small parts of many things, such as medicines and metals.

Applications in various areas

Crystallography helps scientists learn how atoms are arranged in materials. In materials science, it is used to study the shapes and properties of crystals. For example, crystallography can show how iron changes its structure when heated. This helps create new materials with special properties.

In biology, crystallography is important for studying big molecules like proteins and DNA. Scientists use X-ray crystallography to see the shapes of these molecules. This helps us understand how living things work at a very small level. The shapes of these molecules are stored in a database called the Protein Data Bank, which scientists can use for free.

Notation

Main article: Miller index

In crystallography, scientists use special symbols to describe directions and planes in crystals. For example, square brackets like [100] show a direction, while parentheses such as (100) describe a plane in the crystal. Angle brackets or chevrons group similar directions together, and curly brackets or braces group similar planes. These notations help scientists understand how crystals are built and how they behave.

Reference literature

The International Tables for Crystallography are eight books about crystals. These books help scientists learn how to study crystals. They talk about special tools, like x-ray beams, that scientists use to see how crystals are built. Each book has about 1000 pages. The books explain the steps and rules for studying crystals. They do not list every kind of crystal. The books cover topics like crystal symmetry and math tables.

Notable scientists

Crystallography has been helped by many important scientists. Some well-known names are William Henry Bragg, William Lawrence Bragg, Francis Crick, Rosalind Franklin, Dorothy Crowfoot Hodgkin, and Ada Yonath. These scientists and others have done important work. They helped us learn how atoms and molecules are arranged in crystals. Their work lets us understand the structure of materials and living things at the molecular level.