Iacovella, Christopher R. (2006). Periodic boundary conditions. Glotzer group. Depts of Chemical Engineering, Materials Science & Engineering, Macromolecular Science, and Physics, University of Michigan.
Schematic of periodic boundary conditions. When using periodic boundary conditions, a particle which exits the system on the right, will reappear on the left. In the schematic, our
simulation volume is colored in red. As the yellow particle exits on the right, it will re-enter on the left. This can be thought of as having identical simulation boxes surrounding the system. As
the yellow particle enters the next simulation on the right, a particle from the periodic image on the left will enter.