A crystallographer is a scientist who studies the arrangement of atoms in crystalline solids. They use techniques like X-ray diffraction to analyze the structure of crystals, which helps in understanding the properties of materials. This field is important in various applications, including chemistry, biology, and materials science. Crystallographers often work with substances like proteins, minerals, and metals to determine their molecular structures. Their research can lead to advancements in drug development, the creation of new materials, and insights into fundamental scientific questions. By revealing how atoms are organized, crystallographers contribute significantly to many scientific disciplines.