[Pw_forum] Optical properties

[Andrea Ferretti]

Dear Kesong,


> i.  I tested the epsilon.x, and it could read the outputfile by PWSCF3.2. 
> However, it can't read the save file by PW3.0. Is that true?

this is correct, 
the format of the restart file used to change rapidly from one version to 
another... since espresso-3.2 it is instead indented to be much more 
stable and it should be readable also by the next coming versions

> 
> ii. The epsilon.x cann't support the ultra soft PP?
> 

at the moment USPP are not supported: epsilon.x computes the matrix 
elements of the momentum p which are difficult to "augment" in the USPP 
framework (at least within the data stored in the current 
UPF pseudopotential format)...
for the future, note that QE is going to support PAW which is eg one way to 
shortcut the problem

note also that the corrections due to the nonlocal terms in the 
pseudopotentials are not accounted for;

all the best
andrea  


Andrea Ferretti
National Research Center S3, CNR-INFM  ( http://s3.infm.it )
Dip. Fisica, Univ. di Modena e Reggio E. (Italy)
Tel: +39 059 2055301;  Fax: +39 059 374794;  Skype: andrea_ferretti
URL: http://www.nanoscience.unimo.it

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