[QE-users] Memory requirements of projwfc.x in k-resolved case

[Thomas Brumme]

Dear all,

I'm struggling to project the wave functions on atoms in the k-resolved 
case.
The job always crashes because of the memory limit. The system itself is 
quite
large - 2 layers of MoS2 but rotated, total of 138 atoms. The band structure
calculation for 151 k points finished without problems using 1.72 GB RAM
maximum per core (100 cores in total). Starting the projwfc.x run with the
same settings (100 cores, 2 GB RAM per core) the job is killed because it
exceeds the memory. Increasing to 8 GB per core does not solve the problem.

What are the exact memory requirements for projwfc.x for the k-resolved
case? I read in the forums that it shouldn't be more than the corresponding
scf or bands run, should it? Then why does those runs finish and the 
projwfc.x
not? I'm using version 6.2.1 compiled with the old xml format (as I 
started the
calculation when the new XML was not there yet and had to stop in between)
Furthermore, the normal (scf and bands) run are parallelized via the 
standard
R & G space devision on 100 cores. Um, and I'm using the relativistic 
PBE paw
pseudos of the pslibrary, 55 Ry and 440 Ry cutoffs.

Is the code reading in the wave functions of all k points at once, i.e., 
would
it help to reduce the number of k points?

Regards

Thomas

-- 
Dr. rer. nat. Thomas Brumme
Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry
Leipzig University
Phillipp-Rosenthal-Strasse 31
04103 Leipzig

Tel:  +49 (0)341 97 36456

email: thomas.brumme at uni-leipzig.de