CrystalFieldFunction¶

import numpy as np

# This creates a (empty) workspace to use with EvaluateFunction
x = np.linspace(0, 50, 100)
y = x * 0
ws = CreateWorkspace(x, y)

# Define two single site multi-spectrum functions to generate some data to fit to
fun1 = "name=CrystalFieldMultiSpectrum,Ion=Ce,Temperatures=(4, 10), FWHMs=2,Background=\"name=LinearBackground,A0=20,A1=-0.11\","\
       "ToleranceIntensity=0.001,B20=0.37737,B22=3.9770,B40=-0.031787,B42=-0.11611,B44=-0.12544,f1.f0.A0=10,f1.f0.A1=0.09"

fun2 = "name=CrystalFieldMultiSpectrum,Ion=Pr, Symmetry=D4h,Temperatures=(4, 10), FWHMs=2,"\
       "ToleranceIntensity=0.001,B20=0.4268, B40=0.001031, B44=-0.01996, B60=0.00005, B64=0.001563"

# Generate the data
EvaluateFunction(fun1 + ';' + fun2, InputWorkspace=ws, InputWorkspace_1=ws, OutputWorkspace='data')

cf = "name=CrystalFieldFunction,Ions=(Ce, Pr),Symmetries=(C2v, D4h), FixAllPeaks=1,"\
     "Temperatures=(4, 10),FWHMs=2.0,ToleranceIntensity=0.001,Background=\"name=LinearBackground,A0=20,\","\
     "ion0.B20=0.37737,ion0.B22=3.9770,ion0.B40=-0.031787,ion0.B42=-0.11611,ion0.B44=-0.12544,"\
     "ion1.B20=0.4268, ion1.B40=0.001031, ion1.B44=-0.01996, ion1.B60=0.00005, ion1.B64=0.001563,"\
     "ties=(ion0.BmolX=0,ion0.BmolY=0,ion0.BmolZ=0,ion0.BextX=0,ion0.BextY=0,ion0.BextZ=0, ion0.B60=0,ion0.B62=0,ion0.B64=0,ion0.B66=0, ion0.IntensityScaling=1),"\
     "ties=(ion1.BmolX=0,ion1.BmolY=0,ion1.BmolZ=0,ion1.BextX=0,ion1.BextY=0,ion1.BextZ=0, ion1.IntensityScaling=1),"\
     "ties=(sp0.IntensityScaling=1, sp1.IntensityScaling=1),ties=(sp1.bg.A1 = -sp0.bg.A1)"

Fit(cf, InputWorkspace='Workspace_0', WorkspaceIndex=1, InputWorkspace_1='Workspace_1', WorkspaceIndex_1=1, Output='fit')