| Rays are either transmitted through the crystal, reflected off the surface, or diffracted by the crystal lattice | , from the International Union of Crystallography• X-rays may also be produced using a synchotron, which emits a much stronger beam |
|---|---|
| Structure solution Solution of the phase problem leads to the initial electron density map | Single-crystal diffractometers use either 3- or 4-circle goniometers |
For highly symmetric materials, collection can be constrained symmetrically to reduce the collection time.
30| Applications Single-crystal X-ray diffraction is most commonly used for precise determination of a unit cell, including cell dimensions and positions of atoms within the lattice | , from the International Union of Crystallography• A number of different procedures exist for solution of the phase problem, but the most common method currently, due to the prevalence of high-speed computers, is using direct methods and least-squares, initially assigning phases to strong reflections and iterating to produce a refined fit |
|---|---|
| X-rays are generated in a cathode ray tube by heating a filament to produce electrons, accelerating the electrons toward a target by applying a voltage, and impact of the electrons with the target material | A detector records and processes this X-ray signal and converts the signal to a count rate which is then output to a device such as a printer or computer monitor |
All diffraction methods are based on.