$DiffractrumX$

DiffractrumX

Live

A browser-native Rietveld laboratory for powder XRD and neutron PD

From a pattern file to a fitted CIF without an installer, a .pcr dialect, or a server that keeps the run.

Powder diffraction is still reduced, more often than not, in desktop programmes designed in the 1990s and 2000s. They are deep, trusted, and slow to start. A visiting student cannot open a colleague’s refinement on a phone. A paper’s supporting CIF is exported after the fit, not during it.

DiffractrumX is a single web laboratory that already knows the physics of a Rietveld fit — structure factors, Caglioti widths, Thompson–Cox–Hastings pseudo-Voigt, Kα₂, Lorentz and polarisation for X-rays, Sears bound coherent lengths for neutrons — and wraps that engine in a staged instrument a materials scientist can drive in a few minutes. It does not replace an expert FullProf job on a twelve-phase mineral. It does replace the afternoon it takes to get a clean two-phase ceramic onto a CIF.

BaTiO₃ (Pm-3m) powder pattern from the DiffractrumX demonstration. Observed counts and the calculated profile on Cu Kα, Bragg ticks under the trace. Rwp, χ² and GoF live on the same page as the plot.

Difference curve of the same BaTiO₃ refinement. Residual weight away from the Bragg ticks is read as a warning that the cell or profile is unfinished — not as a second phase invented to quiet the plot.

DiffractrumX on the BaTiO₃ demonstration: staged Rietveld, one cubic phase, R-factors, and a fitted CIF on the same instrument.

What it does

Forward model from real structures; demos generated from quartz, corundum, rutile and anatase, then recovered
One lab, two probes: laboratory X-ray (Cu, Co, Mo, Cr, Fe, Ag, custom λ, Kα₂) and constant-wavelength neutron
Constrained Rietveld with staged parameter release; live Rwp, χ² and GoF on the plot
Peak extraction, indexing, Le Bail, and a composition-constrained ab initio path when the cell is unknown
Export that other codes accept: fitted CSV, CIF, FullProf-style PCR, PNG/SVG — the PCR is a bridge, not a lock-in
AI opinion on the stage log after one credit; patterns are never Posted to MatSpace