"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)

:line

change_box command :h3

[Syntax:]

change_box style :pre

style = {ortho} or {triclinic} :l
  {ortho} = convert simulation box from non-orthogonal (triclinic) to orthogonal
  {triclinic} = convert simulation box from orthogonal to non-orthogonal (triclinic) :pre

[Examples:]

change_box ortho
change_box triclinic :pre

[Description:]

By default LAMMPS runs a simulation in an orthogonal, axis-aligned
simulation box.  LAMMPS can also run simulations in "non-orthogonal
(triclinic) simulation boxes"_Section_howto.html#howto_12.  A box is
defined as either orthogonal or non-orthogonal when it is created via
the "create_box"_create_box.html, "read_data"_read_data.html, or
"read_restart"_read_restart.html commands.

This command allows you to toggle the existing simulation box from
orthogonal to non-orthogonal and vice versa.  For example, an initial
equilibration simulation can be run in an orthogonal box, the box can
be toggled to non-orthogonal, and then a "non-equilibrium MD (NEMD)
simulation"_Section_howto.html#howto_13 can be run with deformation
via the "fix deform"_fix_deform.html command.

Note that if the simulation box is currently non-orthogonal and has
non-zero tilt in xy, yz, or xz, then it cannot be converted to an
orthogonal box.

[Restrictions:]

At the point in the input script when this command is issued, no
"dumps"_dump.html can be active, nor can a "fix
ave/spatial"_fix_ave_spatial.html or "fix deform"_fix_deform.html be
active.  This is because these commands test whether the simulation
box is orthogonal when they are first issued.  Note that these
commands can appear in your script before a change_box command is
issued, so long as an "undump"_undump.html or "unfix"_unfix.html
command is also used to turn them off.

[Related commands:] none

[Default:] none