# Periodic Boundaries in Molecular Dynamics Simulations

sqljunkey
In molecular dynamics people use periodic boundaries to confine particles being simulated. I read here that they are used to simulate large "infinite" particle systems. How can I know that the periodic boundary is simulating actual molecular outcomes for a finite particle system that had a large number of atoms?

In other words, is there a way to find how large my particle system has to be to replicate the same outcome that I would get for a periodic system?