Verification

These pages compare EasyDiffraction calculations with reference calculations. Bragg pages (powder/single-crystal) compare against FullProf, an independent program. Pair-distribution-function pages compare against a direct diffpy.pdffit2 calculation — the same library EasyDiffraction wraps, so those pages check wrapper fidelity (correct parameter hand-off) rather than cross-validating the PDF physics against an independent implementation. Each page focuses on one experiment type or one additional model term, and feature names match the Features page. Some pages document a known difference (EasyDiffraction does not yet match the reference for that term); these are marked below and inside the notebook.

Powder, Neutron, Constant Wavelength

LaB6 structure

• pd-neut-cwl LaB6 basic – baseline Pseudo-Voigt powder pattern (cryspy).
• pd-neut-cwl LaB6 isotope – isotope-specific neutron scattering length (¹¹B).
• pd-neut-cwl LaB6 sample displacement – sample displacement and transparency correction (FullProf "SyCos, SySin").
• pd-neut-cwl LaB6 FCJ asymmetry – Finger-Cox-Jephcoat asymmetry (FullProf "Npr=7"). Known difference: the cryspy CW profile has no FCJ term.
• pd-neut-cwl LaB6 absorption – absorption correction (cylinder, Hewat) (FullProf "muR").

La0.5Ba0.5CoO3 structure

• pd-neut-cwl LBCO basic – baseline Pseudo-Voigt powder pattern (cryspy).
• pd-neut-cwl LBCO preferred orientation – March–Dollase preferred orientation (FullProf "Nor=1").

PbSO4 structure

• pd-neut-cwl PbSO4 basic – baseline Pseudo-Voigt powder pattern (cryspy).
• pd-neut-cwl PbSO4 Bérar-Baldinozzi asymmetry – Pseudo-Voigt + Bérar-Baldinozzi asymmetry (FullProf "Asy1-4").

Y2O3 structure

• pd-neut-cwl Y2O3 isotropic ADPs – baseline isotropic ADPs (Biso/Uiso).
• pd-neut-cwl Y2O3 anisotropic β ADPs – anisotropic β-tensor ADPs.

Powder, Neutron, Time-Of-Flight

Fe structure

• pd-neut-tof Fe Pseudo-Voigt – baseline Pseudo-Voigt (non-convoluted) TOF profile (FullProf "Npr=7" TOF).

NCAF structure

• pd-neut-tof NCAF Jorgensen-Von Dreele (Gaussian) – Jorgensen-Von Dreele (back-to-back exponentials ⊗ pseudo-Voigt) profile with the Lorentzian terms (γ₀, γ₁, γ₂) forced to zero, i.e. the Gaussian case (FullProf "Npr=9").

Si structure

• pd-neut-tof Si Jorgensen – Jorgensen (back-to-back exponentials ⊗ Gaussian) profile (FullProf "Npr=9", Gaussian limit).
• pd-neut-tof Si Jorgensen-Von Dreele – Jorgensen-Von Dreele (back-to-back exponentials ⊗ pseudo-Voigt) profile with Lorentzian terms (FullProf "Npr=9").
• pd-neut-tof Si Jorgensen-Von Dreele + size/strain – isotropic microstructural size/strain broadening on the Jorgensen-Von Dreele profile (size_g/strain_g, size_l/strain_l).

Diamond structure

• pd-neut-tof Diamond DREAM – Jorgensen (back-to-back exponentials ⊗ Gaussian) profile fitted to McStas-simulated reduced data from the DREAM diffractometer at ESS (scale-only adjustment between cryspy and FullProf).

Powder, X-Ray, Constant Wavelength

LiF structure

• pd-xray-cwl LiF single wavelength – baseline Cu Kα₁ Pseudo-Voigt pattern (cryspy and crysfml).
• pd-xray-cwl LiF polarization – X-ray Lorentz-polarization correction (FullProf "Cthm, Rpolarz").
• pd-xray-cwl LiF absorption – absorption correction (cylinder, Hewat) (FullProf "muR").
• pd-xray-cwl LiF second wavelength – second wavelength (Cu Kα₁/Kα₂ doublet, FullProf "Lambda2, Ratio"). The doublet is an EasyDiffraction-level implementation (the engine is run twice and summed by the intensity ratio).

PbSO4 structure

• pd-xray-cwl PbSO4 round robin – anglesite X-ray round-robin case (Pseudo-Voigt + Bérar-Baldinozzi asymmetry).

Single Crystal

Pr2NiO4 structure

• sc-neut-cwl Pr2NiO4 basic – neutron, constant wavelength; anisotropic β-tensor ADPs.

Tb2Ti2O7 structure

• sc-neut-cwl Tb2Ti2O7 basic – neutron, constant wavelength; baseline with isotropic ADPs.
• sc-neut-cwl Tb2Ti2O7 isotropic extinction – neutron, constant wavelength; isotropic Becker-Coppens extinction (Gaussian model). Known difference: cryspy and FullProf use different extinction conventions.
• sc-neut-cwl Tb2Ti2O7 anisotropic β ADPs – neutron, constant wavelength; anisotropic β-tensor ADPs.

Taurine structure

• sc-neut-tof Taurine basic – neutron, time-of-flight; isotropic ADPs (without extinction correction).

Powder, Total Scattering (Pair Distribution Function)

Ni structure

• total-neut-cwl Ni Gaussian-damped sinc – Gaussian-damped sinc termination PDF, neutron constant wavelength (pdffit2).

Si structure

• total-neut-tof Si Gaussian-damped sinc – Gaussian-damped sinc termination PDF, neutron time-of-flight (pdffit2).

NaCl structure

• total-xray NaCl Gaussian-damped sinc – Gaussian-damped sinc termination PDF, X-ray (pdffit2).