# lorentz

Ornstein-Zernicke correlation length model

Parameter Description Units Default value
scale Source intensity None 1
background Source background cm-1 0.001
cor_length Screening length 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

$q=\sqrt{q_x^2 + q_y^2}$

References

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.