[lammps-users] lammps-users Digest, Vol 51, Issue 3

Dear Lammps users

I have used nve with Berendsen Thermostat and Berendsen Barostat in lammps for fixing temperature and pressure for water.

The system is approaching the equilibrium.But The volume changes to a very high value(nearly 7 to 8 times the initial value given ).
If anybody faced such a problem please give me a solution for this.
Jesseela S

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Dear Lammps users

      I have used nve with Berendsen Thermostat and Berendsen Barostat

in lammps for fixing temperature and pressure for water.

    The system is approaching the equilibrium\.But The volume changes to

a very high value(nearly 7 to 8 times the initial value given ).
If anybody faced such a problem please give me a solution for this.

simulation programs strictly follow the "garbage in, garbage out" rule.
if you don't get the expected results, you first have to ask yourself,
if the parameters are correct.

lammps is very likely working correctly, but nobody can tell
whether what you have been feeding it as input, is what you
were intending to do. at least not without seeing any details.

cheers,
     axel.

Double check all you parameters. Are they correct? I like to equilibrate water like this; pack the box at the correct uniform density for *your model* (you have the original paper, right?), minimize or use NVE/limit for a bit, and then run NVE with Langevin for a few hundred ps. Write out the pressure when you are doing this. If it's not spot on in the end, run NPT with a small drag.
Matt

Quoting jesseela hamza <[email protected]...>: