[Pw_forum] specific q-point with phonon splitting

[Thomas Gruber]

Dear all,

I am doing phonon calculations with splitting in q-points and 
irreducible representations. Do to negative frequencies at the last 
q-point I do some convergence test only with the last q-point. It is 
possible to calculate the whole q-point at once without calculating the 
other and get the frequencies with "start_q" and "last_q". But I have to 
split into representations because the system is too big. When I run 
final calculation with "recover=.true." then the calculation finds all 
*.xml files but it stop the the error code:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
      from openfilq : error #         1
      file LiSi.k8.q4.tr2-14.0.4.4.wfc not found
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
I found out that when I run a final calculation with several q-points 
and "start_q=1" it works to every q-point, but if start_q is not equal 
to 1 then I get the above error message. Why is it possible to calculate 
a q-point at once but not with splitting?

Best regards,

Thomas Gruber

-- 
Thomas Gruber
Institut für Theoretische Physik
TU Bergakademie Freiberg
Leipziger Str. 23, 09599 Freiberg, Germany
Tel: +49 (0)3731 392006
Email: thomas.gruber at physik.tu-freiberg.de