Abstract
Diffuse scattering is a rich source of information about disorder in crystalline materials, which can be modelled using atomistic techniques such as Monte Carlo and molecular dynamics simulations. Modern X-ray and neutron scattering instruments can rapidly measure large volumes of diffuse-scattering data. Unfortunately, current algorithms for atomistic diffuse-scattering calculations are too slow to model large data sets completely, because the fast Fourier transform (FFT) algorithm has long been considered unsuitable for such calculations [Butler & Welberry (1992). J. Appl. Cryst.25, 391–399]. Here, a new approach is presented for ultrafast calculation of atomistic diffuse-scattering patterns. It is shown that the FFT can actually be used to perform such calculations rapidly, and that a fast method based on sampling theory can be used to reduce high-frequency noise in the calculations. These algorithms are benchmarked using realistic examples of compositional, magnetic and displacive disorder. They accelerate the calculations by a factor of at least 102, making refinement of atomistic models to large diffuse-scattering volumes practical.
Original language | English |
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Pages (from-to) | 14-24 |
Number of pages | 11 |
Journal | Acta Crystallographica Section A: Foundations and Advances |
Volume | 75 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2019 |
Externally published | Yes |
Funding
Funding for this research was provided by: Churchill College, University of Cambridge.
Keywords
- Diffuse scattering
- Disorder
- Monte Carlo simulation