Professor, George Washington University
Crystallography is the science that examines crystals, which can be found everywhere in nature—from salt to snowflakes to gemstones. The properties and inner structures of crystals help scientists to examine the arrangement of atoms in the solid state, and this knowledge is used in fields such as chemistry, physics, and biology.
Crystallographers use X-ray, neutron, and electron diffraction techniques to identify and characterize solid materials. They commonly bring in information from other analytical techniques, including X-ray fluorescence, spectroscopic techniques, microscopic imaging, and computer modeling and visualization to construct detailed models of the atomic arrangements in solids. This provides valuable information on a material's chemical makeup, polymorphic form, defects or disorder, and electronic properties. It also sheds light on how solids perform under temperature, pressure, and stress conditions.
Crystal-growing specialists use a variety of techniques to produce crystalline forms of compounds for use in research or manufacturing. They may be experts in working with hard-to-crystallize materials, or they may grow crystals to exacting specifications for use in computer chips, solar cells, optical components, or pharmaceutical products.
Crystallography has become an important tool for studying structural biology. Proteins and other biological materials (including viruses) may be crystallized to aid in studying their structures and composition. Many important pharmaceuticals are administered in crystalline form, and detailed descriptions of their crystal structures provide evidence to verify claims in patents.
Instrument manufacturers hire crystallographers for customer sales and support functions, including instrument repair and helping customers with special projects. Staff crystallographers at the national laboratories develop and maintain leading-edge research instruments and software capabilities. They also assist visiting users in setting up and running experiments using specialized techniques, including synchrotron X-ray diffraction and neutron diffraction. Universities employ staff members to maintain and operate their research laboratories and to train students to use the instruments.
Crystallographers may develop instrumentation and software for collecting, analyzing, and visualizing data and for translating this data into crystal structure models. Some crystallographers maintain and develop archival databases at industrial and academic institutions, as well as some nonprofits and government laboratories.
Service laboratories hire diffraction technicians to prepare and catalog samples, run the data collections, and prepare routine reports on the results. Technicians may also be called on to perform routine instrument maintenance and simple repairs.
Forensics laboratories use crystallography to investigate cases involving product adulteration or counterfeiting. They may identify minerals, metals, or other materials found at crime scenes. They may also identify corrosion products and other residues found at the site of an industrial accident to help verify the events leading up to the accident.
Laboratory technicians usually require a bachelor's degree in chemistry, biology, geology, physics, or a related field.
Research positions usually require a Ph.D. and additional experience in a field of specialization (pharmaceuticals, structural biology, geosciences, materials science, physics, etc.). Research associates may have master's degrees and some experience.
Customer and user support positions may require a graduate degree, depending on the nature and complexity of the service provided. These positions often require practical experience gained on the job, in addition to a strong academic foundation.
Licenses are not generally required for crystallography.
Crystallographers must take safety training because their laboratory instruments produce X-rays, neutrons, or high-energy electrons. They wear one or more radiation dosimetry devices in the laboratory and must submit these devices for periodic checks to ensure that they have not been exposed to excessive amounts of ionizing radiation.
Crystallographers working at government agencies or national laboratories may be required to undergo background checks or obtain security clearances on the basis of the nature of the work and the security requirements of the laboratory.
Crystallographers generally work in laboratories, and they may be responsible for operating, maintaining, and repairing their instruments. They are also responsible for maintaining sample preparation supplies and equipment and ensuring the safe use and disposal of samples and other materials used in the lab. They may be responsible for training students and other users of the laboratory facilities and for ensuring that they adhere to safety procedures.
Because crystallography is a very computation-intensive specialization, crystallographers must be able to use, and train others on, proper data collection and analysis methods, software packages, and computer visualization capabilities. They may be systems administrators for the computing networks associated with their laboratories.
Crystal-growing labs may have controlled-environment devices, including glove boxes, furnaces, and cryogenic chambers. These spaces must be kept free from contaminants and unwanted sources of vibration or other factors that could damage the crystals as they grow.
Crystallographers in academic environments often teach courses in diffraction theory or provide individualized instruction on using the instruments and software. At national laboratories, crystallographers train visiting users, and they perform their own research and maintain custom-designed instruments, many of which are quite large.
Research crystallographers make presentations at conferences, and they may travel to specialized facilities to run experiments.
Required skills vary according to specialization, but may include the following:
Graduates with bachelor's or associate's degrees can find employment as laboratory technicians or research assistants. Students or recent graduates with an interest in research may do one or more internships in preparation for selecting an area of specialization for a graduate degree.
Research and supervisory positions generally require a master's or doctoral degree, often with several years of postgraduate experience. Postdoctoral fellowships are one way to gain this experience.
Professional-level crystallographers may pursue a teaching and/or research career in academia, or they may oversee a diffraction laboratory in industry or for a government agency or national laboratory. They may also support and train facility users, students, or customers or develop new capabilities for collecting and analyzing data.
After gaining several years of postgraduate experience, crystallographers may move into managing a suite of laboratories, or they may direct research programs.
Advances in instrumentation, software, and automated data analysis and visualization have reduced the need for crystallography specialists in many organizations. Today, crystallography is viewed as one component of a suite of abilities to support research or other work in structural biology, drug discovery, manufacturing processes, chemical synthesis, or other broad areas.
Historically, crystallography was associated with geology, mining, ceramics, and metallurgy. These fields still employ workers with skills in growing and analyzing crystalline materials, but for many years, the largest demand has been in the life sciences and medical fields (structural biology, pharmaceuticals, and related topics).
Although computer hardware and software have evolved to the point where they perform much of the computation, a crystallographer must understand the underlying principles to set up the calculations properly and ensure that the results are meaningful and properly interpreted. Computers can create 3D models of crystal structures, but an ability to correlate these structures with properties of the material requires an ability to visualize and interpret these models. This requires patience and attention to detail.
Crystallographers must collaborate with experts in synthesis and in other analytical techniques, and often, they must have some degree of expertise across several disciplines. They may be required to develop novel sample configurations, adapt their instruments to new applications, or adapt and create new software capabilities to handle unusual or difficult problems.
Crystallographers, especially technicians, may serve a support function for chemical synthesis labs. They may work in commercial service labs or as a part of an in-house analytical team. This requires them to understand the problem that their customers or colleagues are trying to solve, and to devise a data collection and analysis procedure that provides useful and accurate results.
Crystallography specialists find opportunities working in instrument and software development, customer support for instrument manufacturing companies, user support at national laboratories, or working in crystal-growing laboratories.
Crystallographers have been associated with the geosciences, metallurgy, and ceramics engineering. However, the largest areas of demand today are in the medical and life sciences.