Resonant Inelastic X-ray Scattering(RIXS)

Using the option *-x* and *-xa* the RIXS cross section can be calculated
by *mcdisp*.
Option *-x* calculates resonant inelastic x-ray intensities
maximized with respect to azimuth.
Option *-xa* calculates resonant inelastic x-ray
intensities with complete azimuth dependence for each reflection.

The formalism is based on [27, equ.8 ff], e.g. the observables are the 9 components ( =xx xy xz yx yy yz zx zy zz) of the tensor , which is related to the operator in [27] by

(61) |

Here the vector describes the polarisation of the incoming / outgoing photon beam (linear (real) or circular polarized (complex) light). Vector components (e.g. to the xyz coordinate system, where , and perpendicular to and .

For the isotropic ion the scattering operator is given by

In order to use this expression, the conductivities have
to be entered in the *sipf* file, e.g.

SIGMA0r=1.32 SIGMA1r=1.32 SIGMA2r=1.32 SIGMA0i=1.32 SIGMA1i=1.32 SIGMA2i=1.32('r' and 'i' stand for real and imaginary part, respectively).

Note: in module *so1ion* the scattering operator
is given in terms of the total angular momentum
instead
of
.

If a more complex tensor is required, it's components can be defined in the sipf file using the perlparse option.