[Pw_forum] calculate the XANES in absolute energy scale using QE

[Giuseppe Mattioli]

Dear Felix
You haven't found because it is not possible... As far as I know the only case which allows for 
absolute (usually not very accurate) estimates of XANES peaks is the one related to gas phase 
molecules, with the sample mixed with a non interacting species (like CO2, e. g.,  in the case of 
C(1s)-->unoccupied states transitions) providing an appropriate reference. I do not know about XANES 
(i. e., xspectra.x) calculations applied to extended systems and reproducing absolute absorption 
values. People usually align one of the calculated peaks with its measured counterpart.

HTH

Giuseppe

On Monday 11 February 2013 21:57:19 Feng Tian wrote:
> Dear users and developers,
>                                              I have a question about how to
> do the XANES in absolute scale which can be compared to experiments.  I
> haven't found any tutorial for this, so could anyone give some instructions
> or direction to some  instructions. Thanks a lot.
> 
> 
> Best
> Felix

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   Giuseppe Mattioli                            
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