Out of range atoms - cannot compute PPPM

Dear all,

I heated a region of atoms by the following command. The time step is 1fs.

fix 1 all heat 10000 0.01 region 1
fix 2 all press/berendsen iso 1.0 1.0 10000
run 1100000

I want to heat the region but also to control pressure so that the size of the system could changed itself.

But it faced the error ‘Out of range atoms - cannot compute PPPM’ .

How can I solve it?

Thank you.

Z.Q Liao

The doc page for Section errors explains this error message
and common causes. You likely have bad dynamics. First
try running without those 2 fixes and see if the system is stable,
then try press/berendsen, and verify the system volume is
stable, then add fix heat.

Steve

Dear Steve,
Thanks. It didn’t face the error before I add press/berendsen. This command made it a mistake.

My system was added by read_restart which I use npt to lead it to equilibrium.
units real
dimension 3
boundary p p p
atom_style full
pair_style lj/cut/coul/long 9.0 9.0
bond_style harmonic
angle_style harmonic
kspace_style pppm 1.0e-4
read_restart water.restart
neghbor 2.0bin
neigh_modify delay 0 every 1 check yes

The start state list as following.
Temp 295.01286 Press 616.09555 Volume 60827.311……

How to solve this problem?

Z.Q Liao

I don’t know. The error section of the manual explains
why this error occurs. You need to figure out why
the dynamics of the system are going bad.

Steve

Dear Steve,
I have tried a lot of ways to solve this problem but failed. I changed the"pair_style lj/cut/coul/long 9 9" to"pair_style lj/cut/coul/cut 9 9" but failed also. So I rebuilt the system this morning. I hope that is helpful.

And I have another question.I have read a paper. It said that the system was controlled by Nose-Hoover and Parrinilo一Rahman in the equilibrium stage at first.Then the Nose-Hoover temperature control was removed in the disequilibrium stage.I have tried NPT followed by fix press/berendsen but failed. Is it result in “Berendsen”?

I wonder what command the author use.

Thank you.

Dear Steve,

I have something forgot. When I changed the pair_style, the error isn’t “out of range atoms-cannot compute PPPM” any more. But when the system run 20000 steps, the press and energy is NAN.

I’m so sorry to trouble you. But I’m new to LAMMPS and I have no one to discuss this kind of questions around. I need to think over all the questions except asking for help to “LAMMPS Users Mailing List”.

Thanks again.

Z.Q Liao

This indicates bad dynamics. If you output thermo info frequently (e.g.
every step), you should see things going bad long before NaNs appear.

Steve

Dear Steve,
I have sent two emails to you. I think that you only received one.so I list my first question here again.

And I have another question.I have read a paper. It said that the system was controlled by Nose-Hoover and Parrinilo一Rahman in the equilibrium stage at first.Then the Nose-Hoover temperature control was removed in the disequilibrium stage.I have tried NPT followed by fix press/berendsen but failed. Is it result in “Berendsen”?

I wonder what command the author use.