Two-phase fit: YAlO₃ and Al₂O₃, SPODI¶

The same staged fit as the Python and Command line tutorials, in the app. Its structure and experiment come from EasyDiffraction's collection with Load ▾ From web…, and each stage frees its parameters in the Parameters table on Analysis before the fit.

Create a project¶

Press Start on Home, then Create a new project, and give it a name.

Load the structures¶

On Structure, choose Load ▾ From web…, search for each entry by its id and click it:

• pd-neut-cwl_yalo3-al2o3-spodi-YAlO3
• pd-neut-cwl_yalo3-al2o3-spodi-Al2O3

Load the experiment¶

On Experiment, choose Load ▾ Full experiment From web…, search for each entry by its id and click it:

• pd-neut-cwl_yalo3-al2o3-spodi-spodi

Set the minimizer¶

On Analysis → Extra, set the Minimizer as the case's project does: the Shift/s.u. stop rule and room for more iterations.

Start with nothing free¶

On Analysis, open the Free column header of the Parameters table and fix every parameter, so the stages below free one group at a time.

Cells, scales and 2θ zero¶

Both phases' cells and scales, and the zero shift, put the peaks of both phases in place.

Filter the Cell parameters of YAlO3 and Al2O3, choosing each in the datablock filter using the category filter, the Linked structures parameters of spodi, choosing each in the datablock filter using the category filter and the Instrument parameters with calib in their name of spodi, choosing each in the datablock filter using the category filter and the name filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Background¶

Choose spodi in the datablock filter, then filter the Background parameters using the category filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Peak widths¶

The Gaussian widths and the mixing η₀.

Choose spodi in the datablock filter, then filter the Peak broadening parameters using the category filter and the Peak mixing parameters with eta_0 in their name using the category filter and the name filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Asymmetry¶

The four Bérar-Baldinozzi asymmetry terms.

Choose spodi in the datablock filter, then filter the Peak asymmetry parameters using the category filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Atom positions¶

The coordinates the symmetry leaves free in both phases.

Filter the Atomic coordinates parameters of YAlO3 and Al2O3, choosing each in the datablock filter using the category filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Displacements¶

Every site's displacement in both phases.

Filter the Atomic displacement parameters using the category filter, click the Free column header and choose Free · all, then press Fit in the status bar.

Correlations¶

The Correlations view on Analysis shows which fitted parameters move together.

Report¶

The Report page collects the structure, the experiment and the fit.