Professor, George Washington University
Crystallography is the science that examines crystals, which can be found everywhere in nature—from salt to snowflakes to gemstones. Crystallographers use the properties and inner structures of crystals to determine the arrangement of atoms and generate knowledge that is used by chemists, physicists, biologists, and others. Within the past century, crystallography has been a primary force in driving major advances in the detailed understanding of materials, synthetic chemistry, the understanding of basic principles of biological processes, genetics, and has contributed to major advances in the development of drugs for numerous diseases. As a science, crystallography has produced 28 Nobel Prizes, more than any other scientific field.
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.
Single-crystal X-ray crystallography is widely considered to be the gold standard for establishing the structures of crystalline solids. This method is used to establish patent claims, establish structure-property relationships for new compounds, and many other applications. However, powder crystallography instrumentation and data analysis software have emerged over the past 30 years as powerful methods for investigating the structures of materials that cannot be studied with single-crystal methods. Powder methods are used in a wide variety of investigations, including forensic analyses, identifying components of mixtures, and identifying properties of polymers and other poorly crystallized materials.
The pharmaceutical and biochemical fields rely extensively on crystallographic studies. 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.
Some crystallographers 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 typically have master's degrees and some laboratory 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 directing research programs.
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).
The crystallography field is rapidly evolving. While advances in instrumentation, software, and automated data analysis and visualization have reduced the need for crystallography specialists in some chemical areas, many crystallographers work in both hardware and software improvement and are often behind the improvement of the technology that allows the solution of structures that could not be solved even a decade ago. These technological improvements have also resulted in more effective and streamlined structure determination. There are still many challenges to be solved when it comes to structural biology, which still require crystallography. Crystallographers are part of a cadre of interdisciplinary scientists that work to understand diverse processes.
In the life sciences, has advanced to the level where crystallographers must be highly proficient and trained in molecular biology, protein chemistry, protein expression and purification methods, biophysics, and computer science in order to tackle major scientific questions. Such a rigorous scientific training background makes graduates in crystallography highly competitive for many career options in a variety of scientific professions. Crystallographers are involved at the forefront of major discoveries in the life sciences, medicinal chemistry, and materials science. Crystallographers combine their multi-disciplinary to address some of the most challenging questions in developing atomic-level insights into major biological processes such as DNA repair, ribosome biogenesis, cell signaling, and cancer biology. Crystallographers are involved heavily in designing experiments and analyzing data to develop precise models of many of these biological processes.
The advancement and creation of new materials used in medicine, optics, electronics, and other technologies requires a detailed understanding of the atomic-arrangement of the materials. Crystallographers are involved in developing new methodologies to better characterize these materials by X-ray diffraction methods and improving the chemical methods used in synthesizing these materials.
Although computer hardware and software in some fields 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.