[QE-users] Raman spectra with GGA

[Giuseppe Mattioli]

Dear Karolina

AFAIK gradient corrections have been never "officially" implemented in  
ph.x RAMAN calculations and you are stuck at LDA level. I saw Ari  
Seitsonen's slides you mention (I suppose), and in the last slide  
there is actually this caveat

Limitations: Beyond LDA only with shortcuts

If you want to know such shortcuts you should ask Ari, or the Authhors  
of the graphene nanoribbon paper (if you find it, because it is not  
cited in the slides).

HTH
Giuseppe

Karolina Milowska <karolina.milowska at gmail.com> ha scritto:

> Dear All,
>
> Recently, I have came across files and slides from MASTANI Summer School
> from 2014, in particular - the calculation of Raman spectrum of graphene
> nanoribbon. I would like to reproduce this example. Unfortunately, version
> 6.3 doesn't allow me to do that.
>
> This is he error message:
>   
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      Error in routine phq_setup (1):
>      third order derivatives not implemented with GGA
>   
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> May I ask you where can I find the version of qe which has this
> implementation?
>
> Kind regards,
> Karolina



GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
Via Salaria Km 29,300 - C.P. 10
I-00015 - Monterotondo Scalo (RM)
Mob (*preferred*) +39 373 7305625
Tel + 39 06 90672342 - Fax +39 06 90672316
E-mail: <giuseppe.mattioli at ism.cnr.it>