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# CrystalFieldPeaks¶

## Description¶

This function calculates energies and intensities of transitions between states of a crystal electric field acting upon a rare earth ion. It is a part of crystal field computation in Mantid and under active development. More documentation will follow as the development progresses.

Here is an example of how the function can be evaluated from python. The output is a TableWorkspace with two columns: the first column with the energies (in meV) and the second one with the intensities (in milibarn per steradian). The function doesn’t require an input workspace so None is passed for InputWorkspace property of EvaluateFunction.

fun = 'name=CrystalFieldPeaks,Ion=Ce,Temperature=25.0,B20=0.37737,B22=3.9770,B40=-0.031787,B42=-0.11611,B44=-0.12544'
EvaluateFunction(fun, None, OutputWorkspace='out')


## Attributes (non-fitting parameters)¶

Name

Type

Default

Description

Ion

String

Mandatory

An element name for a rare earth ion. Possible values are: Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb.

Symmetry

String

C1

A symbol for a symmetry group. Setting Symmetry automatically zeros and fixes all forbidden parameters. Possible values are: C1, Ci, C2, Cs, C2h, C2v, D2, D2h, C4, S4, C4h, D4, C4v, D2d, D4h, C3, S6, D3, C3v, D3d, C6, C3h, C6h, D6, C6v, D3h, D6h, T, Td, Th, O, Oh

Temperature

Double

1.0

A temperature in Kelvin.

ToleranceEnergy

Double

$$10^{-10}$$

Tolerance in energy in meV. If difference between two or more energy levels is smaller than this value they are considered degenerate.

ToleranceIntensity

Double

$$10^{-3}$$

Tolerance in intensity. If difference between intensities of two or more transitions is smaller than this value the transitions are considered degenerate.

## Properties (fitting parameters)¶

Name

Default

Description

BmolX

0.0

The x-component of the molecular field.

BmolY

0.0

The y-component of the molecular field.

BmolZ

0.0

The z-component of the molecular field.

BextX

0.0

The x-component of the external field.

BextY

0.0

The y-component of the external field.

BextZ

0.0

The z-component of the external field.

B20

0.0

Real part of the B20 field parameter.

B21

0.0

Real part of the B21 field parameter.

B22

0.0

Real part of the B22 field parameter.

B40

0.0

Real part of the B40 field parameter.

B41

0.0

Real part of the B41 field parameter.

B42

0.0

Real part of the B42 field parameter.

B43

0.0

Real part of the B43 field parameter.

B44

0.0

Real part of the B44 field parameter.

B60

0.0

Real part of the B60 field parameter.

B61

0.0

Real part of the B61 field parameter.

B62

0.0

Real part of the B62 field parameter.

B63

0.0

Real part of the B63 field parameter.

B64

0.0

Real part of the B64 field parameter.

B65

0.0

Real part of the B65 field parameter.

B66

0.0

Real part of the B66 field parameter.

IB21

0.0

Imaginary part of the B21 field parameter.

IB22

0.0

Imaginary part of the B22 field parameter.

IB41

0.0

Imaginary part of the B41 field parameter.

IB42

0.0

Imaginary part of the B42 field parameter.

IB43

0.0

Imaginary part of the B43 field parameter.

IB44

0.0

Imaginary part of the B44 field parameter.

IB61

0.0

Imaginary part of the B61 field parameter.

IB62

0.0

Imaginary part of the B62 field parameter.

IB63

0.0

Imaginary part of the B63 field parameter.

IB64

0.0

Imaginary part of the B64 field parameter.

IB65

0.0

Imaginary part of the B65 field parameter.

IB66

0.0

Imaginary part of the B66 field parameter.

IntensityScaling

1.0

A scaling factor for peak intensities.

Categories: FitFunctions | General