[ase-users] A possible bug in dftd3.py

[MURAOKA Koki]

Dear ASE developers,

Hi,
Thank you for developing such an amazing software.

I’m currently trying to perform a DFT-D3 calculation using ASE and GPAW on
a cluster.
I found that my parallel job occasionally fails with an error message that
claims the input file for dftd3 is empty.
The cause seems to be line 262 (write_vasp(fname, atoms)) and line 265
(write_xyz(fname, atoms, plain=True)) in ase/calculators/dftd3.py where all
processes try to write input files for dftd3 at the same time.
As a result, when the root process tries to execute dftd3, sometimes the
input file of dftd3 is being empty or broken because another process is in
the middle of processing the input file.

Simply ensuring only the root process writes the input file for dftd3 by
inserting `if world.rank == 0:` can resolve the issue.
I guess the root of the problem discussed in a previous thread (
https://listserv.fysik.dtu.dk/pipermail/ase-users/2017-October/004006.html)
is similar.

If my guess is correct, I’m ready to send a pull request to resolve this
issue.
Thanks!

--
Koki Muraoka
UTokyo
-- 
## --
# 村岡 恒輝 / Koki MURAOKA
## --
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listserv.fysik.dtu.dk/pipermail/ase-users/attachments/20180824/e3e8771f/attachment.html>