[ase-users] NEB parallel with Abinit parallel

[Ask Hjorth Larsen]

Hi,

Am Mo., 19. Nov. 2018 um 14:51 Uhr schrieb Kondov, Ivan (SCC) via
ase-users <ase-users at listserv.fysik.dtu.dk>:
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> Dear all,
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> I think that the ASE/NEB and the Calculator can run both in parallel only if the Calculator is GPAW. This is because the NEB and the process spawned by the Calculator have to share an MPI communicator (I am not sure about any existing tricks with application/machinefiles and mpirun options). Thus parallel NEB will work with VASP or Abinit in serial mode only. Also serial NEB will work with the parallel versions of VASP, Abinit etc.
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> In order to run a parallel NEB with parallel VASP, the NEB implementation in the VTST package can be used (http://theory.cm.utexas.edu/vasp/) and VASP has to be patched. For Abinit I do not know such a solution.
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> A generic solution with ASE could be to split the calculations of the images in each BFGS iteration into several jobs and distribute them on the cluster. After all jobs are ready then their outputs are collected and passed to BFGS and the next image geometries are computed, distributed and so on until BFGS converges. Unfortunately I do not have an implementation yet but I would prefer (and recommend) to use a workflow system such as FireWorks for this.

We can perhaps modify the new SocketIOCalculator to accept and control
multiple connections.  That would make it possible to launch a server
(on any computer) and then a job with, say, 10 nodes, and each node
connects to the server in order to receive positions and then
calculate forces.  I can help if any of you are willing to take the
initiative.

Best regards
Ask

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> Best regards,
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> Ivan
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