How Many Monomer Repeat Units are Necessary for Reliable Molecular Dynamics Simulation?

Abstract

This study was an attempt to answer the question, “How many monomer repeat units are necessary in molecular dynamics simulation in order to obtain reliable (i.e. repeatable) solutions?” A series of numerical tests was conducted to provide an answer. Based on the numerical results, reliable solutions required approximately ten thousand monomer repeat units at minimum, which was the sum of the monomer units in every polymer chain molecule. It did not matter much whether there were longer chain polymer molecules in a small quantity or shorter chain polymer molecules in a large quantity. What was critical was the total number of monomer repeat units. For a particle reinforced composite that consists of metallic atoms embedded in a polymer matrix, the minimum number of total monomer repeat units in the polymer matrix was approximately five thousand for reliable solutions.