# XANES Absolute cross-section

### From FEFF

The absolute cross section can be obtained from the output in ‘xmu.dat’. Look for this line:

xsedge+100, used to normalize mu 2.5908E-04

Since our distances are in , we report cross section also in . If you multiply the 4-th or 5-th column by this normalization value you will obtain the cross section in . Often the absolute cross section is reported in barns, which have a simple connection with our units (1 = 100Mbarn).

Note that this normalization can be switched off using the ABSOLUTE card. This is set by default for ELNES and EXELFS calculation. The normalization factor will then show as "1.0".

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### Calculation Strategies and Examples

XANES calculations

- Need for SCF and additional difficulties for XANES
- GeCl4 Molecule
- Solid: XANES and LDOS
**Absolute cross-section**

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