SelectCellWithForm dialog.
Table of Contents
Select a conventional cell with a specific form number, corresponding to the UB stored with the sample for this peaks works space.
| Name | Direction | Type | Default | Description |
|---|---|---|---|---|
| PeaksWorkspace | InOut | PeaksWorkspace | Mandatory | Input Peaks Workspace |
| FormNumber | Input | number | Mandatory | Form number for the desired cell |
| Apply | Input | boolean | False | Update UB and re-index the peaks |
| Tolerance | Input | number | 0.12 | Indexing Tolerance |
| NumIndexed | Output | number | The number of indexed peaks if apply==true. | |
| AverageError | Output | number | The average HKL indexing error if apply==true. | |
| AllowPermutations | Input | boolean | True | Allow permutations of conventional cells |
| TransformationMatrix | Output | dbl list | The transformation matrix |
Given a PeaksWorkspace with a UB matrix corresponding to a Niggli
reduced cell, this algorithm will allow the user to select a
conventional cell corresponding to a specific form number from the
Mighell paper. If the apply flag is not set, the information about the
selected cell will just be displayed. If the apply flag is set, the
UB matrix associated with the sample in the PeaksWorkspace
will be updated to a UB matrix corresponding to the selected
cell AND the peaks will be re-indexed using the new UB matrix.
The output transformation matrix 
will change 
to 
and map each 
vector to 
. It can be further
used by the TransformHKL algorithm.
NOTE: The possible conventional cells, together with the corresponding errors
in the cell scalars can be seen by running the
ShowPossibleCells algorithm, provided the
stored UB matrix corresponds to a Niggli reduced cell.
This algorithm is based on the paper: Alan D. Mighell, Lattice Symmetry and Identification—The Fundamental Role of Reduced Cells in Materials Characterization. Journal of research of the National Institute of Standards and Technology 106.6 (2001): 983, available from: nvlpubs.
Example:
ws=LoadIsawPeaks("TOPAZ_3007.peaks")
FindUBUsingFFT(ws,MinD=8.0,MaxD=13.0)
print("Lattice before SelectCellWithForm:")
lattice = ws.sample().getOrientedLattice()
print(" ".join("{:.9f}".format(x) for x in [lattice.a(), lattice.b(), lattice.c(),
lattice.alpha(), lattice.beta(), lattice.gamma()]))
SelectCellWithForm(PeaksWorkspace='ws', FormNumber=25, Apply=True)
print("\nLattice after SelectCellWithForm:")
lattice = ws.sample().getOrientedLattice()
print(" ".join("{:.9f}".format(x) for x in [lattice.a(), lattice.b(), lattice.c(),
lattice.alpha(), lattice.beta(), lattice.gamma()]))
Output:
Lattice before SelectCellWithForm:
8.605818643 11.935925461 11.941812766 107.429088323 98.752912466 98.951193475
Lattice after SelectCellWithForm:
14.131051152 19.247332564 8.605818643 89.881170675 105.071333770 89.970386662
Categories: AlgorithmIndex | Crystal\Cell
C++ source: SelectCellWithForm.cpp (last modified: 2019-10-10)
C++ header: SelectCellWithForm.h (last modified: 2018-10-05)