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  2. X-ray crystallography - Wikipedia

    en.wikipedia.org/wiki/X-ray_crystallography

    The use of computational methods for the powder X-ray diffraction data analysis is now generalized. It typically compares the experimental data to the simulated diffractogram of a model structure, taking into account the instrumental parameters, and refines the structural or microstructural parameters of the model using least squares based ...

  3. Coot (software) - Wikipedia

    en.wikipedia.org/wiki/Coot_(software)

    Coot can also display electron density, which is the result of structure determination experiments such as X-ray crystallography and EM reconstruction. The density is contoured using a 3D-mesh. The contour level controlled using the mouse wheel for easy manipulation - this provides a simple way for the user to get an idea of the 3D electron ...

  4. Rietveld refinement - Wikipedia

    en.wikipedia.org/wiki/Rietveld_refinement

    The most common powder X-ray diffraction (XRD) refinement technique used today is based on the method proposed in the 1960s by Hugo Rietveld. [2] The Rietveld method fits a calculated profile (including all structural and instrumental parameters) to experimental data.

  5. X-ray diffraction - Wikipedia

    en.wikipedia.org/wiki/X-ray_diffraction

    X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering , when there is no change in the energy of the waves.

  6. X-ray diffraction computed tomography - Wikipedia

    en.wikipedia.org/wiki/X-ray_diffraction_computed...

    X-ray diffraction computed tomography is an experimental technique that combines X-ray diffraction with the computed tomography data acquisition approach. X-ray diffraction (XRD) computed tomography (CT) was first introduced in 1987 by Harding et al. [ 1 ] using a laboratory diffractometer and a monochromatic X-ray pencil beam .

  7. Direct methods (electron microscopy) - Wikipedia

    en.wikipedia.org/wiki/Direct_methods_(electron...

    Kinematical Diffraction; One of the reasons direct methods was originally developed for analyzing X-ray diffraction is because almost all X-ray diffraction is kinematical. While most electron diffraction is dynamical, which is more difficult to interpret, there are instances in which mostly kinematical scattering intensities can be measured ...

  8. R-factor (crystallography) - Wikipedia

    en.wikipedia.org/wiki/R-factor_(crystallography)

    In crystallography, the R-factor (sometimes called residual factor or reliability factor or the R-value or R Work) is a measure of the disagreement between the crystallographic model and the experimental X-ray diffraction data - lower the R value lower is the disagreement or better is the agreement.

  9. Wide-angle X-ray scattering - Wikipedia

    en.wikipedia.org/wiki/Wide-angle_X-ray_scattering

    It is an X-ray-diffraction [2] method and commonly used to determine a range of information about crystalline materials. The term WAXS is commonly used in polymer sciences to differentiate it from SAXS but many scientists doing "WAXS" would describe the measurements as Bragg/X-ray/powder diffraction or crystallography.