3.5

CreateLeBailFitInput v1

../_images/CreateLeBailFitInput-v1_dlg.png

CreateLeBailFitInput dialog.

Summary

Create various input Workspaces required by algorithm LeBailFit.

Properties

Name Direction Type Default Description
ReflectionsFile Input string   Name of [http://www.ill.eu/sites/fullprof/ Fullprof] .hkl file that contains the peaks. Allowed extensions: [‘.hkl’]
FullprofParameterFile Input string Mandatory Fullprof’s .irf file containing the peak parameters. Allowed extensions: [‘.irf’]
GenerateBraggReflections Input boolean False Generate Bragg reflections other than reading a Fullprof .irf file.
MaxHKL Input int list 12,12,12 Maximum reflection (HKL) to generate
Bank Input number 1 Bank ID for output if there are more than one bank in .irf file.
LatticeConstant Input number Mandatory Lattice constant for cubic crystal.
InstrumentParameterWorkspace Output TableWorkspace Mandatory Name of Table Workspace Containing Peak Parameters From .irf File.
BraggPeakParameterWorkspace Output TableWorkspace Mandatory Name of Table Workspace Containing Peaks’ Miller Indices From .prf File.

Description

This algorithm is to import Fullprof .irf file (peak parameters) and .hkl file (reflections) and record the information to TableWorkspaces, which serve as the inputs for algorithm LeBailFit.

Format of Instrument parameter TableWorkspace

Instrument parameter TableWorkspace contains all the peak profile parameters imported from Fullprof .irf file.

Presently these are the peak profiles supported

* Thermal neutron back to back exponential convoluted with pseudo-voigt (profile No. 10 in Fullprof)

Each row in TableWorkspace corresponds to one profile parameter.

Columns include Name, Value, FitOrTie, Min, Max and StepSize.

Format of reflection TableWorkspace

Each row of this workspace corresponds to one diffraction peak. The information contains the peak’s Miller index and (local) peak profile parameters of this peak. For instance of a back-to-back exponential convoluted with Gaussian peak, the peak profile parameters include Alpha, Beta, Sigma, centre and height.

How to use algorithm with other algorithms

This algorithm is designed to work with other algorithms to do Le Bail fit. The introduction can be found in the wiki page of Le Bail Fit.

Usage

Example - create inputs for LeBail fit of Pg3:

CreateLeBailFitInput(ReflectionsFile=r'LB4854b3.hkl',
      FullprofParameterFile=r'2013A_HR60b3.irf',
      Bank='3',
      LatticeConstant='4.1568899999999998',
      InstrumentParameterWorkspace='PG3_Bank3_ParTable',
      BraggPeakParameterWorkspace='LaB6_HKL_Table')

# Examine
partablews = mtd["PG3_Bank3_ParTable"]
braggtablews = mtd["LaB6_HKL_Table"]
print "Number Bragg peaks from .hkl file is %d.  Number of peak profile parameters is %d." % (braggtablews.rowCount(), partablews.rowCount())

Output:

GeneraateHKL? =  False
Number Bragg peaks from .hkl file is 76.  Number of peak profile parameters is 30.

Categories: Algorithms | Diffraction | Utility