Yes it took little more than 5 days to compute only the first q-point.
anyway it seems that I should use 1x1x1 grid instead of 2x2x2. But are
you suggesting to do the single mode calculation with 1x1x1 grid or
the "mode=full" using the 1x1x1 grid?
Yes, but no need to do it: you have done it already. You can just call
d3_qq2rr and specify "1 1 1" as the grid size:
ls anh*| d3_qq2rr.x 1 1 1
and it will automatically compute the force constants from the
calculation at (0,0,0). This way you can immediately test how it works.
If you want to try the 2x2x2 grid, I would use 10 pools and maybe try
with *fewer* CPUs per pool: at the moment you are using 128 which
requires a lot of communications. If the calculation fits in RAM, I
would recommend keeping each pool on a single computing node.
You may try to use some local scratch in order to avoid running out of
disk space (ask the cluster managers what to use).
Finally, if you manage to get everything running, you can run al the
q-points triplet simultaneously as different batch jobs by setting
"first" and "last". You can have the same outdir and prefix, as long as
they work on different triplets, they will not interfere (this is true
for d3q, but not in general for other linear response codes)
hth
Regards,
Kanka
Kanka Ghosh
Postdoctoral Researcher
I2M-Bordeaux
University of Bordeaux, CNRS UMR 5295
Site: Ecole Nationale Supérieure des Arts et Métiers
Bordeaux-Talence 33400
------------------------------------------------------------------------
*From: *"Lorenzo Paulatto" <[email protected]>
*To: *"users" <[email protected]>
*Sent: *Friday, December 4, 2020 9:09:50 AM
*Subject: *Re: [QE-users] D3Q code stopped due to davcio error
Thanks for pointing out the storage issue. Yes, I am running it at
the French computing centre (University of Bordeaux's cluster
system (curta, mcia)). Here I am attaching the d3q output file.
Indeed, it was in the process of computing the second q-point triplet.
I do not have access to Bordeaux cluster, but I could ask it if you
need that I look at the code. That said, I see that to compute the
first q-point it took about 5 days, it will take at least a month to
do the second point ! Because it has less symmetry the code needs to
compute 2x more k-points and 3x more perturbations.
"Maybe for such a large system you can get some decent
force-constants already from (0,0,0) alone"
In that case, you mean to implement the "mode=gamma-only" tag?
Not really, the triple (0,0,0) is in itself the 1x1x1 grid, and you
can threat it as such. Thanks to some Fourier interpolation trickery,
you can use it to get the D3 matrices at any point. Also, the d3_qq2rr
code is not particularly optimized, and is not parallelized I'm not
sure you would manage to compute the Fourier transform of the 2x2x2
grid anyway.
You have to keep in mind that the 3-body force constant become huge
very quickly with the number of atoms and the size of the grid: each
D3 matrix has (3*nat)^3 complex elements, and a grid n x n x n
contains n^6 power triplets
In your case, the 2x2x2 grid would use about 2.2GB of RAM, which is
probably still feasible, but i would try the 1x1x1 first.
cheers
Regards,
Kanka
Kanka Ghosh
Postdoctoral Researcher
I2M-Bordeaux
University of Bordeaux, CNRS UMR 5295
Site: Ecole Nationale Supérieure des Arts et Métiers
Bordeaux-Talence 33400
------------------------------------------------------------------------
*From: *"Lorenzo Paulatto" <[email protected]>_
*To: *"users" <[email protected]>
*Sent: *Thursday, December 3, 2020 11:23:58 PM
*Subject: *Re: [QE-users] D3Q code stopped due to davcio error
task # 71
from davcio : error # 5011
error while writing from file
".//D3_Q1.0_0_0_Q2.0_0_-1o2_Q3.0_0_1o2/scf.d1.dq1pq1.72"
I guess it may have run out of space, d3q uses a ton of disk space
and there is not easy way to avoid this. If you are running on any
of the French computing centers I can try to have a look directly.
I do not think the change in number of CPUs could cause this
problem, but if you provide the full output I can check. Also, 44
atoms is a lot for the d3q code, it seems like you're running the
second q-point triplet, which is of kind (0,q,-q), it takes much
more time and disk space than the triplet (0,0,0). Maybe for such
a large system you can get some decent force-constants already
from (0,0,0) alone
cheers
Kanka Ghosh
Postdoctoral Researcher
I2M-Bordeaux
University of Bordeaux, CNRS UMR 5295
Site: Ecole Nationale Supérieure des Arts et Métiers
Bordeaux-Talence 33400
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing [email protected]
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_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
