Dear LAMMPS users,
The version I’m using is LAMMPS (7 Aug 2019).
I’m trying to apply a constant shear stress to my system.
According to a quote from Steve from an archive in 2008, I can simply apply periodic boundary conditions and use “fix npt” to control the shear stress. And LAMMPS will keep the system periodic.
“When ghost atoms are created for a tilted (triclinic)box, the shift factor is applied to coords of the ghost atoms, so the interactions don’t see the boundaries, just as if there were no tilt.”
However, I would like to try it this way:
1.add vacuum to my system to make it non-periodic along the z-direction
2.define the top and bottom layers
- fix 1 top addforce -2408 0.0 0.0
fix 2 bottom addforce 2408 0.0 0.0
fix 5 mobile npt temp 350 350 1000 x 0 0 10000 y 0 0 10000 z 0 0 10000 drag 0.0
Nonetheless, the shape of the box didn’t change, and the stresses were close to 0.
If I didn’t make my question clear to you, please let me know and I will improve it.
Corresponding part of log.lammps is attached below: