What is periodic boundary conditions?

Periodic boundary conditions are a technique used in computational simulations to simulate an infinite system with a finite computational domain. These boundary conditions assume that the system being studied is periodic, meaning that it repeats itself in all directions.

In periodic boundary conditions, when a particle or object leaves the computational domain through one boundary, it reenters through the opposite boundary as if the boundaries were connected. This allows for the simulation of an effectively infinite system without the need to model the entire system.

Periodic boundary conditions are commonly used in molecular dynamics simulations, lattice-based models, and finite element analysis. They help to reduce artificial effects from the finite size of the simulation domain and allow for more accurate representation of physical systems.

However, periodic boundary conditions can introduce artifacts and complications in simulations, such as the formation of artificial interactions between particles that would not occur in a non-periodic system. It is important to carefully consider the implications of using periodic boundary conditions in a simulation and to choose the appropriate boundary conditions based on the specific system being studied.