[Pw_forum] Restarting phonon calculation with images, possibility of changing the number of images

[Thomas Brumme]

Dear all,

I have a question concerning the restart possibilities with image 
parallelization in a phonon calculation.
I have the problem that for some of the images the calculation did not 
converge. I know that I can achieve
convergence by reducing the mixing since I encountered the problem 
before for exactly the same system.
Yet, now, as some of the images are finished with their task (or close 
to), I have only the possibility of either
using only one image copying the dynmat.$iq.$ir.xml files to the 
_ph0/*.phsave/ directory, or to restart using
the same number of images and live with the fact that some images will 
do nothing...
Or is there a third possibility I don't know? Wouldn't it be better to 
first check what has already been done
and then distributing the work among the images? Or is this too hard to 
code? (I haven't looked at this part
of the code yet)

OK, I think I could also use some kind of GRID parallelization and 
create some input files by hand, setting
the start_irr, start_q, and so on, but this is rather tedious since I 
have a big system and a q-point grid...
So, again the (maybe stupid) question: Is there another possibility?

Regards

Thomas


-- 
Dr. rer. nat. Thomas Brumme
Max Planck Institute for the Structure and Dynamics of Matter
Luruper Chaussee 149
22761 Hamburg

Tel:  +49 (0)40 8998 6557

email: Thomas.Brumme at mpsd.mpg.de