Periodic Boundaries in Molecular Dynamics Simulations

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Periodic boundaries in molecular dynamics simulations are essential for modeling large, "infinite" particle systems by confining particles. To ensure that the outcomes of a finite particle system align with those of a periodic system, one approach is to increase the size of the particle system and compare results. Doubling the system size can help determine if the outcomes converge, indicating that the periodic boundary conditions are effectively simulating the desired molecular behavior. Experimentation is crucial in validating the accuracy of the simulation results. Ultimately, the size of the particle system must be sufficient to replicate the behavior observed in periodic simulations.
sqljunkey
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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?
 
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One thing you can do is let the experiment decide !
 
sqljunkey said:
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?
Redo the calculation with double the size system and see how the answers compare.
 

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