Can not replicate with fixes that store atom quantities

Hi,
I am trying to replicate the simulation box. I am using reaxff as pair
style with reax charge equilibration fix:
fix 2 all qeq/reax 100 0.0 10.0 1.0e-6 reax/c
if I use replicate command after this fix it gives this error:

Can not replicate with fixes that store atom quantities.

I tried unfix qeq part and still gives same error. Is it a bug ?
dundar.

Hi,
I am trying to replicate the simulation box. I am using reaxff as pair style
with reax charge equilibration fix:
fix 2 all qeq/reax 100 0.0 10.0 1.0e-6 reax/c
if I use replicate command after this fix it gives this error:

Can not replicate with fixes that store atom quantities.

I tried unfix qeq part and still gives same error. Is it a bug ?

please provide one (or more) small(!) test(s) that reliably reproduce this.

in the meantime, you should be able to work around it through using a
write_data, clear, read_data sequence.

axel.

Hi,
I am trying to replicate the simulation box. I am using reaxff as pair style
with reax charge equilibration fix:
fix 2 all qeq/reax 100 0.0 10.0 1.0e-6 reax/c
if I use replicate command after this fix it gives this error:

Can not replicate with fixes that store atom quantities.

I tried unfix qeq part and still gives same error. Is it a bug ?

please provide one (or more) small(!) test(s) that reliably reproduce this.

in the meantime, you should be able to work around it through using a
write_data, clear, read_data sequence.

or write_restart, clear, read_restart

i would not call it a bug, but a known limitation. since you can
easily work around it by writing a restart or data file and reading it
back after clearing the internal state, this is not a serious problem.
after all, you are not likely to replicate the system many times.

axel.

Hi,

maybe you can replicate the system before fix qeq/reax? It works.

Regards,
Oleg

dundar yilmaz <[email protected]…24…> 4 апреля 2014 г. 11:21:00 написал:

Hi,

maybe you can replicate the system before fix qeq/reax? It works.

i think the general idea is to first equilibrate a smaller system and
then replicate it to a larger box and equilibrate some more.
considering the computational cost of ReaxFF calculations, that would
result in significant time savings.

axel.

Thats right, equilibriate a small system and replicate it. Ideally unfix command should take care of the fix but even unfixing all fixes will not solve the problem. Maybe unfixing is not totally free all arrays related to the fix. That might be an issue.
dundar.

Agree. In that case writing one restart or data file and using it later for large simulations is probably the best approach.

Oleg

Axel Kohlmeyer <[email protected]> 4 апреля 2014 г. 17:31:36 написал:

As Axel said, it’s a restriction on using replicate. A fix
that stores per-atom quantities has no rules for how to
replicate those quantities to new replicated atoms.
It might be much more complicated than simple copying
the value. E.g. fix shake which stores the topology
of shake clusters.

So we don’t allow it. The solution is simple, as Oleg

says. Just unfix and such fixes that exist, do your replication,
than redefine any of those fixes you need.

Steve