neutronpy.crystal.MagneticFormFactor.calc_mag_form_fac

MagneticFormFactor.calc_mag_form_fac(q=None, g=None, qrange=None)

Calculate the magnetic form factor of an ion.

Parameters:

q : float or list, optional

An array of values or position at which the form factor should be calcuated.

g : float, optional

The g-factor, which is 2 is left undefined.

qrange : float, optional

The range of q over which the form factor should be calculated, if no input array q is provided.

Returns:

output : tuple

(form factor, q, j₀, j₂, j₄)

Notes

The magnetic form factor of an ion is given by:

\[f(q) = <j_0(q)> + (\frac{2}{g}-1)<j_2(q)> \mathrm{(Jensen and Mackintosh,1991)}\]

using the 3-gaussian approximation to \(f(q)\) from the International Tables of Crystallography (by J. Brown)