Periodic boundary in LIGGGHTS and LAMMPS: differences in simulation setup?

Submitted by rangr1 on Thu, 07/26/2018 - 12:55

I am trying to setup a simple one particle simulation with periodic boundary conditions (PBC) in LIGGGHTS and LAMMPS. I am finding that the atoms are lost in LIGGGHTS-PUBLIC (v3.8.0 ), whereas the same simulation except for a minor change in the communicate command seems to work fine in LAMMPS (17 Nov 2016). Please let me know if I have to include additional commands when I try to set up PBC in LIGGGHTS. I have attached the minimal examples for your reference.

AttachmentSize
Plain text icon LIGGGHTS input script580 bytes
Plain text icon LAMMPS input script584 bytes

Daniel Queteschiner | Thu, 07/26/2018 - 13:35

a) Use a block region instead of prism, i.e. region reg block 0 10 0 10 0 10 units box
b) If you want to compare the behaviour of LIGGGHTS and LAMMPS you should use the LAMMPS version that LIGGGHTS is based on, i.e. LAMMPS (23 Nov 2013).

rangr1 | Thu, 07/26/2018 - 15:04

The reason I want to use a triclinic box is to do a shear simulation later. Can you let me know the details as to why a block's results should be different from prism's?

Apparently, the input script gives the same result as LAMMPS in v3.4.1 of LIGGGHTS according to my colleague.

Daniel Queteschiner | Thu, 07/26/2018 - 16:31

In that case I suggest to post this as a bug report for the developers at DCS.

jagan1mohan | Sun, 03/08/2020 - 23:34

Hello Daniel and Rangr1,

Greetings. In order to use triclinic box with particles, I'm starting with an orthogonal periodic cube filled with particles. When I use nve/sphere in LIGGGHTS, particles stay inside and move across periodic boundary(s) as expected. When I convert this box into triclinic, either by "0 0 0 XY XZ YZ" header or "change_box", I loose all particles within few time steps when I use nve/sphere. Can we identify what could be the solution to address this situation? I want to use this triclinic box to apply shear on XY plane but I'm unable to hold particles within even without any applied forces.

Thank you,
Jagan Mohan.