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 $[n_{mode n_{hkl}]$.

See Also

spinw | spinw.spinwave | sw_neutron