Evaluation of reactive force fields for prediction of the thermo-mechanical properties of cellulose I_β

Molecular dynamics simulation is commonly used to study the properties of nanocellulose-based materials at the atomic scale. It is well known that the accuracy of these simulations strongly depends on the force field that describes energetic interactions. However, since there is no force field developed specifically for cellulose, researchers utilize models parameterized for other materials. In this work, we evaluate three reactive force field (ReaxFF) parameter sets and compare them with two commonly-used non-reactive force fields (COMPASS and GLYCAM) in terms of their ability to predict lattice parameters, elastic constants, coefficients of thermal expansion, and the anisotropy of cellulose I_β. We find that none is able to accurately predict these properties. However, for future studies focused on a given property, this paper presents the information needed to identify the force field that will yield the most accurate results.