Scattering methods and citations

AmorphGen implements standard scattering conventions in amorphgen/analysis/rdf.py, exposed through StructureAnalyser and the CLI. Cite the software version used, together with the sources relevant to the calculation. The repository’s CITATION.cff contains the software citation.

Sources used by the implementation

Topic	Reference
Total-scattering normalization and correlation-function conventions	Keen, J. Appl. Cryst. 34 (2001), 172–177
Faber–Ziman partial weighting	Faber & Ziman, Philos. Mag. 11 (1965), 153–173
q-dependent X-ray form factors	Waasmaier & Kirfel, Acta Cryst. A 51 (1995), 416–431
Coherent neutron scattering lengths	Sears, Neutron News 3 (1992), 26–37

The direct method evaluates atomic scattering amplitudes at nonzero reciprocal-lattice vectors and averages over spherical shells. It subtracts the self-scattering contribution to produce Faber–Ziman S(q) with a high-q limit of 1. X-ray weights use q-dependent neutral-atom form factors, not constant atomic numbers. See S(q) and XRD: methodology notes for the equations.

Reporting a calculation

A methods description should state:

• The AmorphGen version, input configurations, cell sizes and temperature.

• Whether structure_factor_direct() or the FT-based structure_factor() was used, and the scattering weights.

• The q range, number of bins and smoothing width; for the FT method, rmax.

• The normalization of the experimental reference and any additional instrument or sample corrections.

For example, after filling in the settings actually used:

Structure factors were computed with AmorphGen by summing atomic scattering amplitudes over the periodic cells’ reciprocal-lattice vectors and averaging into spherical q shells. X-ray weights used the Waasmaier–Kirfel neutral-atom form factors. The self-scattering term was removed using the Faber–Ziman normalization.

Add the software and method citations to this description. If reporting an XRD intensity profile, also describe the conversion from normalized S(q) to coherent intensity and the measurement-specific corrections. Agreement with another package or an experiment should be supported by a reproducible comparison of the same inputs and conventions.