sw_xray#

Syntax#

spectra = sw_xray(spectra,Name,Value)

Description#

spectra = sw_xray(spectra,Name,Value) calculates x-ray scattering intensity for non-resonant inelastic x-ray scattering on phonons.

Input Arguments#

spectra: Input structure that contains the displacement-displacement correlation function.

Name-Value Pair Arguments#

'formfact'

If true, the magnetic form factor is included in the spin-spin correlation function calculation. The form factor coefficients are stored in obj.unit_cell.ff(1,:,atomIndex). Default value is false.

'formfactfun'

Function that calculates the magnetic form factor for given \(Q\) value. value. Default value is @sw_mff, that uses a tabulated coefficients for the form factor calculation. For anisotropic form factors a user defined function can be written that has the following header:

F = formfactfun(atomLabel,Q)

where the parameters are:

F row vector containing the form factor for every input \(Q\) value
atomLabel string, label of the selected magnetic atom
Q matrix with dimensions of \([3\times n_Q]\), where each column contains a \(Q\) vector in \(Å^{-1}\) units.

'fid'

Defines whether to provide text output. The default value is determined by the fid preference stored in swpref. The possible values are:

0 No text output is generated.
1 Text output in the MATLAB Command Window.
fid File ID provided by the fopen command, the output is written into the opened file stream.

Output Arguments#

spectra

Structure that is same as the input with the following additional fields:

param Input parameters.
Sperp \(S_\perp(i_{mode},\mathbf{Q})\) x-ray scattering cross section, stored in a matrix with dimensions of \([n_{mode n_{hkl}]\).