ortho = convert simulation box from non-orthogonal (triclinic) to orthogonal
  triclinic = convert simulation box from orthogonal to non-orthogonal (triclinic) 

Examples:

change_box ortho
change_box triclinic 

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. A box is defined as either orthogonal or non-orthogonal when it is created via the create_box, read_data, or read_restart 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 can be run with deformation via the fix deform 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:

When this command is used, no dumps can be defined, nor can fix ave/spatial or fix deform be defined. This is because these commands test whether the simulation box is orthogonal or not when they are first issued.

Related commands: none

Default: none