A test on reactive force fields for the study of silica dimerization reactions

Area of Science:

• Computational Chemistry
• Materials Science
• Chemical Physics

Background:

• Silica dimerization is critical in various chemical processes.
• Accurate simulation of silica behavior requires reliable computational methods.
• Existing methods for parameterizing reactive force fields may contain inherent limitations.

Purpose of the Study:

• To investigate silica dimerization reactions using density functional theory (DFT) and ReaxFF.
• To evaluate the accuracy of standard force field fitting procedures.
• To identify and address discrepancies between DFT and ReaxFF simulations.

Main Methods:

• Utilized density functional theory (DFT) for electronic structure calculations.
• Employed two parameterizations of ReaxFF (reactive force field) for molecular dynamics.
• Performed constrained geometry optimizations and single-point energy calculations across methods.
• Conducted molecular dynamics simulations to observe reaction dynamics.

Main Results:

• Identified unphysical geometries predicted by ReaxFF, even under unreactive conditions.
• Observed spurious reactions during molecular dynamics simulations with both ReaxFF parameterizations.
• Highlighted significant discrepancies between DFT and ReaxFF predictions.

Conclusions:

• Standard force field fitting procedures can lead to inaccurate predictions of molecular behavior.
• A mutual comparative method is necessary to improve the reliability of force field parameterization.
• Further refinement of simulation methodologies is needed for accurate silica reaction studies.