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Crystallization is the process by which solids form, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposition directly from a gas.
Crystallography is used by materials scientists to characterize different materials. In single crystals, the effects of the crystalline arrangement of atoms is often easy to see macroscopically because the natural shapes of crystals reflect the atomic structure. In addition, physical properties are often controlled by crystalline defects.
Crystals used in X-ray crystallography may be smaller than a millimeter across. Although crystallography can be used to characterize the disorder in an impure or irregular crystal, crystallography generally requires a pure crystal of high regularity to solve the structure of a complicated arrangement of atoms.
learning the systematics of crystal and glass chemistry. understanding how physical and chemical properties are related to crystal structure and microstructure. studying the engineering significance of these ideas and how they relate to foreign products: past, present, and future. Topics studied are: Chemical bonding, Electronegativity
All crystals have translational symmetry in three directions, but some have other symmetry elements as well. For example, rotating the crystal 180° about a certain axis may result in an atomic configuration that is identical to the original configuration; the crystal has twofold rotational symmetry about this axis.
In chemistry, fractional crystallization is a stage-wise separation technique that relies on the liquid–solid phase change. This technique fractionates via differences in crystallization temperature and enables the purification of multi-component mixtures, as long as none of the constituents can act as solvents to the others. Due to the high ...
Protein structures are usually determined from either 2-dimensional crystals (sheets or helices), polyhedrons such as viral capsids, or dispersed individual proteins. Electrons can be used in these situations, whereas X-rays cannot, because electrons interact more strongly with atoms than X-rays do. Thus, X-rays will travel through a thin 2 ...
For other solvents of crystallization, analysis is conveniently accomplished by dissolving the sample in a deuterated solvent and analyzing the sample for solvent signals by NMR spectroscopy. Single crystal X-ray crystallography is often able to detect the presence of these solvents of crystallization as well. Other methods may be currently ...