I am simulating SPCE water with lj/cut/coul/long potential. But when i ran it, i got error: ERROR on proc 0: out of range atoms - cannt compute PPPM. How to fix such problem? I checked the mannual for the error part, but i didnt find the solving. Thanks !
From skimming previous threads on thsi topic, it seems likely that
at some point in your simulation (often at the beginning) some atoms
were too close together and/or the forces are too large. This occur
for many reasons. Probably the first thing to do however is to
minimize and equilibrate the system at constant pressure (before your
main production simulation). During equilibration, try increasing the
frequency of neighboring, reducing the timestep. (to 1fs or less),
and increasing the "Pdamp" paramter to at least 1000fs. (A non-zero
"drag" parameter might help. See
http://lammps.sandia.gov/doc/fix_nh.html). As a reference, once
equilibrated, it should eventually be possible to use a 2 fs timestep
with SPC/E if you are also using "fix shake".
See these threads:
-- excerpt from documentation: --
"Out of range atoms - cannot compute PPPM
One or more atoms are attempting to map their charge to a PPPM grid
point that is not owned by a
processor. This is likely for one of two reasons, both of them bad.
First, it may mean that an atom near the
boundary of a processor's sub-domain has moved more than 1/2 the
neighbor skin distance without
neighbor lists being rebuilt and atoms being migrated to new
processors. This also means you may be
missing pairwise interactions that need to be computed. The solution
is to change the re-neighboring
criteria via the neigh_modify command. The safest settings are "delay
0 every 1 check yes". Second, it
may mean that an atom has moved far outside a processor's sub-domain
or even the entire simulation box.
This indicates bad physics, e.g. due to highly overlapping atoms, too
large a timestep, etc."