Parameterization of a molecular dynamics force field is essential in realistically modeling the physicochemical processes involved in a molecular system. This step is often challenging when the equations involved in describing the force field are complicated as well as when the parameters are mostly empirical. ReaxFF is one such reactive force field which uses hundreds of parameters to describe...

We report a study of dynamic cracking in a silicon single crystal in which the ReaxFF reactive force field is used for several thousand atoms near the crack tip, while more than 100,000 atoms are described with a nonreactive force field. ReaxFF is completely derived from quantum mechanical calculations of simple silicon systems without any empirical parameters. Our results reproduce experimenta...

We develop here the methodology for dramatically accelerating the ReaxFF reactive force field based reactive molecular dynamics (RMD) simulations through use of the bond boost concept (BB), which we validate here for describing hydrogen combustion. The bond order, undercoordination, and overcoordination concepts of ReaxFF ensure that the BB correctly adapts to the instantaneous configurations i...

We report a study of dynamic cracking in a silicon single crystal in which the ReaxFF reactive force field is used for several thousand atoms near the crack tip while more than 100,000 atoms of the model system are described with a simple nonreactive force field. The ReaxFF is completely derived from quantum mechanical calculations of simple silicon systems without any empirical parameters. Our...

In order to describe possible reaction mechanisms involving amino acids, and the evolution of the protonation state of amino acid side chains in solution, a reactive force field (ReaxFF-based description) for peptide and protein simulations has been developed as an expansion of the previously reported glycine parameters. This expansion consists of adding to the training set more than five hundr...

Adri C. T. van Duin,†,| Siddharth Dasgupta,‡ Francois Lorant,§ and William A. Goddard III*,‡ Department of Fossil Fuels and EnVironmental Geochemistry, Drummond Building, UniVersity of Newcastle, Newcastle upon Tyne NE1 7RU, United Kingdom, Materials and Process Simulation Center, Beckman Institute (139-74), DiVision of Chemistry and Chemical Engineering, California Institute of Technology, Pas...

In part 1 of this series we developed the reactive force field ReaxFF, choosing the parameters adjusted to fit quantum mechanics description of prototypical reactions. In the present paper we use ReaxFF for reactive dynamics (RD) simulation of thermal decomposition of a siliconcontaining polymer, hydridopolycarbosilane (HPCS) over a wide range of temperature. Many properties of the material dur...

To investigate the initial chemical events associated with high-temperature gas-phase oxidation of hydrocarbons, we have expanded the ReaxFF reactive force field training set to include additional transition states and chemical reactivity of systems relevant to these reactions and optimized the force field parameters against a quantum mechanics (QM)-based training set. To validate the ReaxFF po...

Copper ions play crucial roles in many enzymatic and aqueous processes. A critical analysis of the fundamental properties of copper complexes is essential to understand their impact on a wide range of chemical interactions. However the study of copper complexes is complicated by the presence of strong polarization and charge transfer effects, multiple oxidation states, and quantum effects like ...

We have parameterized a reactive force field (ReaxFF) for lithium–aluminum silicates using density functional theory (DFT) calculations of structural properties of a number of bulk phase oxides, silicates and aluminates, as well as of several representative clusters. The force field parameters optimized in this study were found to predict lattice parameters and heats of formation of selected co...