Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast Calculation of Diffuse Scattering from Atomistic Models   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, J. Appl. Cryst. 25, 391 (1992)]. 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 100, making
refinement of atomistic models to large diffuse-scattering volumes practical.

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The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
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The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph