Problem using Tri and cylindrical

Hello dear LAMMPS users,

I am having a problem with a simulation, I am using an npt ensemble with a triclinical (tri) barostat because of the type of material, when I define the region to be a prism it works flawless.

Now I want to do the same type of simulation but on a cylindrical nanowire. I use an identical script where only the region definition is changed from prism to cylinder. The atom creation is done fine but right after that I obtain this error:

ERROR: Can not specify Pxy/Pxz/Pyz in fix nvt/npt/nph with non-triclinic box (…/fix_nh.cpp:395)

Can someone enlighten me why does this happens? Is it because the faces of the box are not aligned anymore to the faces of the bulk? Is there a workaround this error without having to declare as iso/aniso?

Thank you so much for your kindness and help,

Mario Muralles

Hello dear LAMMPS users,

I am having a problem with a simulation, I am using an npt ensemble with a
triclinical (tri) barostat because of the type of material, when I define
the region to be a prism it works flawless.

Now I want to do the same type of simulation but on a cylindrical
nanowire. I use an identical script where only the region definition is
changed from prism to cylinder. The atom creation is done fine but right
after that I obtain this error:

ERROR: Can not specify Pxy/Pxz/Pyz in fix nvt/npt/nph with non-triclinic
box (../fix_nh.cpp:395)

Can someone enlighten me why does this happens? Is it because the faces of
the box are not aligned anymore to the faces of the bulk? Is there a
workaround this error without having to declare as iso/aniso?

​the error message is self-explanatory. you obviously have not changed your
simulation box to allow triclinic deformation.

​axel.​

Thank you for your prompt response,

Just for future references I worked around this by defining a prism vacuum box and inside it the cylinder containing the atoms.

Thanks again,

Mario