Search results
Results from the WOW.Com Content Network
Multiple data sets may be necessary for certain phasing methods. For example, multi-wavelength anomalous dispersion phasing requires that the scattering be recorded at least three (and usually four, for redundancy) wavelengths of the incoming X-ray radiation. A single crystal may degrade too much during the collection of one data set, owing to ...
The pseudo-Voigt function, like the Gaussian and Lorentz functions, is a centrosymmetric function, and as such does not model asymmetry. This can be problematic for non-ideal powder XRD data, such as those collected at synchrotron radiation sources, which generally exhibit asymmetry due to the use of multiple focusing optics.
MM XRD: Free open-source: Java 3D applet or standalone program: Ovito: MM XRD EM MD: Free open-source: Python [13] [14] PyMOL: MM XRD SMI EM: Open-source [15] Python [16] [self-published source?] According to the author, almost 1/4 of all published images of 3D protein structures in the scientific literature were made via PyMOL. [citation ...
The Patterson function is used to solve the phase problem in X-ray crystallography.It was introduced in 1935 by Arthur Lindo Patterson while he was a visiting researcher in the laboratory of Bertram Eugene Warren at MIT.
The advent of sophisticated automated segmentation technologies, along with their incorporation into public imaging data repositories, greatly enhances the interpretation process. [ 20 ] Volume rendering reveals internal macromolecular structures without segmentation, providing a non-invasive view inside the molecules.
calculation of () Radial distribution function for the Lennard-Jones model fluid at =, =.. In statistical mechanics, the radial distribution function, (or pair correlation function) () in a system of particles (atoms, molecules, colloids, etc.), describes how density varies as a function of distance from a reference particle.
To see where the Scherrer equation comes from, it is useful to consider the simplest possible example: a set of N planes separated by the distance, a. The derivation for this simple, effectively one-dimensional case, is straightforward. First, the structure factor for this case is derived, and then an expression for the peak widths is determined.
Powder diffraction data are usually presented as a diffractogram in which the diffracted intensity, I, is shown as a function either of the scattering angle 2θ or as a function of the scattering vector length q. The latter variable has the advantage that the diffractogram no longer depends on the value of the wavelength λ.