Hi Fabien,
Mg2Si is a small structure with 2 irreducible positions in the IBZ. Here is the
struct file:
Mg2Si cubic 225 Fm-3m
F LATTICE,NONEQUIV.ATOMS 2 225 Fm-3m
MODE OF CALC=RELA unit=bohr
11.999761 11.999761 11.999761 90.000000 90.000000 90.000000
ATOM 1: X=0.00000000 Y=0.00000000 Z=0.00000000
MULT= 1 ISPLIT= 2
Si NPT= 781 R0=.000050000 RMT= 2.39 Z: 14.00000
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
ATOM 2: X=0.25000000 Y=0.25000000 Z=0.25000000
MULT= 2 ISPLIT= 2
2: X=0.25000000 Y=0.25000000 Z=0.75000000
Mg NPT= 781 R0=.000050000 RMT= 2.50000 Z: 12.00000
LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000
0.0000000 1.0000000 0.0000000
0.0000000 0.0000000 1.0000000
48 NUMBER OF SYMMETRY OPERATIONSThe number of k-points is 72 (12x12x12), RmtKmax is 7, GMAX=12 (for test purpose, usually I set it to 24). Best, Pascal Pascal Boulet — Professor in computational materials - DEPARTMENT OF CHEMISTRY University of Aix-Marseille - Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50 Email : pascal.bou...@univ-amu.fr <mailto:pascal.bou...@univ-amu.fr> > Le 15 août 2020 à 11:40, Tran, Fabien <fabien.t...@tuwien.ac.at> a écrit : > > Hi, > > For calculations on small cells with many k-points it is more preferable (for > speediness) to use k-point paralllelization instead of MPI parallelization. > And, as mentioned by PB, MPI applied to small matrices may not work. > > Of course, if the number of cores that you have at disposal is larger (twice > for instance) than the number of k-points in the IBZ, then you can combine > the k-point and MPI parallelizations (two cores for each k-point). > > An example of .machines file for k-point parallelization is (supposing that > you have 6 k-points in the IBZ and want to use one machine having 6 cores): > > lapw0: n1071 n1071 n1071 n1071 n1071 n1071 > dstart: n1071 n1071 n1071 n1071 n1071 n1071 > nlvdw: n1071 n1071 n1071 n1071 n1071 n1071 > 1:1071 > 1:1071 > 1:1071 > 1:1071 > 1:1071 > 1:1071 > granularity:1 > extrafine:1 > > The six lines "1:1071" mean that lapw1, lapw2 and hf are k-point (no MPI) > parallelized (one line fore each core). lapw0, dstart and nlvdw are MPI > parallelized. In this example, the omp parallelization is ignored by > supposing that OMP_NUM_THREADS is set to 1. > > Besides, I find your computational time with HF as very large. What is the > number of atoms in the cell, the number of k-points (plz, specify th n1xn2nx3 > k-mesh), RKmax, etc.? > > Best, > FT > > From: Wien <wien-boun...@zeus.theochem.tuwien.ac.at> on behalf of pboulet > <pascal.bou...@univ-amu.fr> > Sent: Saturday, August 15, 2020 10:35 AM > To: A Mailing list for WIEN2k users > Subject: Re: [Wien] Wien post from pascal.bou...@univ-amu.fr (Errors with > DGEMM and hybrid calculations) > > Dear Peter, > > Thank you for your response. It clarifies some points for me. > > I have run another calculation for Mg2Si, which is a small system, on 12 > cores (no MKL errors!). The job ran for 12 hours (CPU time limit I set) and > made only 3 SCF cycles without converging. > > The .machines file I use looks like this: > > 1:1071:12 > lapw0: n1071 n1071 > dstart: n1071 n1071 > nlvdw: n1071 n1071 > granularity:1 > extrafine:1 > > I guess I am not optimising the number of cores w.r.t. the size of the > problem (72 k-points, 14 HF bands, 12 occupied +2 unoccupied). > > I changed the number of processors for 72, hoping for a 1 k-point/core > parallelisation and commenting all the lines of .machines except granularity > and extrafine. I got less than 1 cycle in 12 hours. > > What should I do to run the HF part on k-points parallelisation only (no > mpi)? This point that is not clear for me from the manual. > > Thank you > Best regards > Pascal > > Pascal Boulet > — > Professor in computational materials - DEPARTMENT OF CHEMISTRY > > University of Aix-Marseille - Avenue Escadrille Normandie Niemen - F-13013 > Marseille - FRANCE > Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50 > Email : pascal.bou...@univ-amu.fr > > Le 12 août 2020 à 14:12, Peter Blaha <pbl...@theochem.tuwien.ac.at> a écrit : > > Your message is too big to be accepted. > > Anyway, the DGEMM messages seem to be a relict of the mkl you are using, and > most likely is related to the use of too many mpi-cores for such a small > matrix. At least when I continue your Mg2Si calculations (in k-parallel mode) > the :DIS and :ENE are continuous, which means that the previous results are > ok. > > Concerning hf, I don't know. Again, running this in sequential (k-point > parallel) mode is no problems and converges quickly. > > I suggest that you change your setup to a k-parallel run for such small > systems. > > Best regards > Peter Blaha > > --------------------------------------------------------------------- > Subject: > Errors with DGEMM and hybrid calculations > From: > pboulet <pascal.bou...@univ-amu.fr> > Date: > 8/11/20, 6:31 PM > To: > A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at> > > Dear all, > > I have a strange problem with LAPACK. I get an error message with wrong > parameters sent to DGEMM, but still wien2k (19.2) seems to converge the scf. > Is that possible? What could be the "problem"? > > I have attached an archive containing the summary of the SCF + compilation > options + SLURM output file. The error message is in the dayfile. > The same error shows up with Wien2k 18.1. > > Actually this case is a test case for testing hybrid calculations as I have > problems with my real case, which is found to be metallic with PBE. At least > Mg2Si is a small band gap semiconductor. > > When I go ahead with the HSE06 functional and Mg2Si I get a different error: > segmentation fault during the hf run. As Mg2Si is a small system I guess this > is not a memory problem: the node is 128GB. > Note that the same problem occurs for my real case file, but the LAPACK > problem does not occur. > > The second archive contains some files related to the hybrid calculation. > > Some hints would be welcome as I am completely lost in these (unrelated) > errors! > > Thank you. > Best regards, > Pascal > > > Pascal Boulet > -- > > P.Blaha > -------------------------------------------------------------------------- > Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna > Phone: +43-1-58801-165300 FAX: +43-1-58801-165982 > Email: bl...@theochem.tuwien.ac.at WIEN2k: http://www.wien2k.at > WWW: http://www.imc.tuwien.ac.at/TC_Blaha > -------------------------------------------------------------------------- > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
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