The vacuum space required for the ribbon under buckling?

Dear All

I want to compress a BN ribbon so that it buckles. Should I consider the vacuum space only in two dimensions (length and width) of the ribbon or should it be in all three dimensions? and how much should this vacuum usually be?

Thanks
Reza

If you use “m” boundary conditions in the buckling dimension, you won’t need to worry about the amount of vacuum, since LAMMPS will automatically expand the box as needed.