The FDMNES program calculates the spectra of different
spectroscopies related to the real or virtual absorption of
x-ray in material. It gives the absorption cross sections of
photons
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they alway ...
around the ionization edge, that is in the energy range of
XANES. The calculation is performed with all conditions of rectilinear or
circular polarization. In the same way, it calculates the structure factors and intensities of anomalous or resonant diffraction spectra (DAFS or RXS).
The code uses two techniques of monoelectronic calculations. The first one is based on the Finite Difference Method (
FDM) to solve the
Schrödinger equation. In that way the shape of the potential is free and in particular avoid the
muffin-tin approximation. The second one uses the Green formalism (
multiple scattering) on a muffin- tin potential. This approach can be less precise but is faster.
FDMNES is used as external program to calculate basic spectra for XANES fitting using
FitIt.
It can also be used to calculate
X-ray Raman scattering spectra.
References
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External links
FDMNES home page
Physics software
Computational chemistry software
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