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## lorentz

Ornstein-Zernicke correlation length model

Parameter | Description | Units | Default value
--- | --- | --- | ---
scale | Scale factor or Volume fraction | None | 1
background | Source background | cm-1 | 0.001
cor_length | Screening length | Å | 50

The returned value is scaled to units of cm-1 sr-1, absolute scale.

Lorentz (Ornstein-Zernicke Model)

Definition

The Ornstein-Zernicke model is defined by

\[I(q)=\frac{\text{scale}}{1+(qL)^2}+\text{background}\]

The parameter \(L\) is the screening length cor_length.

For 2D data the scattering intensity is calculated in the same way as 1D, where the \(q\) vector is defined as

\[q=\sqrt{q_x^2 + q_y^2}\]

Fig. 112 Figure 1: 1D plot corresponding to the default parameters of the model.

Source

`lorentz.py` \(\ \star\ \) `lorentz.c`

References

1. L.S. Qrnstein and F. Zernike, Proc. Acad. Sci. Amsterdam 17, 793 (1914), and Z. Phys. 19, 134 (1918), and 27, 761 {1926); referred to as QZ.

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