Recently quantum mechanical (QM) calculations on a single Si-PETN (silicon-pentaerythritol tetranitrate) molecule were used to explain its colossal sensitivity observed experimentally in terms of a unique Liu carbon-silyl nitro-ester rearrangement (R3Si-CH2-O-R2→ R3Si-O-CH2-R2). In this paper we expanded the study of Si-PETN from a single molecule to a bulk system by extending the ReaxFF reacti...

Simulating chemical reactions involving billions of atoms has been a dream of scientists, with broad societal impacts. This paper realizes the dream through novel simulation methods, algorithms, and parallel computing and visualization techniques. We have designed O(N) embedded divide-and-conquer (EDC) algorithms for 1) first principles-based parallel reactive force-field (P-ReaxFF) molecular d...

We introduce the first reactive force field (ReaxFF) for Mo/Se/H interactions, which enables large-scale molecular dynamics simulations of synthesis, processing, and characterization 2D-MoSe2 whose parameters are trained primarily on first-principles energetics data including both periodic non-periodic calculations. This new potential elucidates structural transition from metallic to semiconduc...

Silicon (Si) has been recognized as a promising anode material for the next-generation high-capacity lithium (Li)-ion batteries because of its high theoretical energy density. Recent in situ transmission electron microscopy (TEM) revealed that the electrochemical lithiation of crystalline Si nanowires (c-SiNWs) proceeds by the migration of the interface between the lithiated Si (LixSi) shell an...

We have used reactive force field (ReaxFF) to investigate the mechanism of interaction of alanes on Al(111) surface. Our simulations show that, on the Al(111) surface, alanes oligomerize into larger alanes. In addition, from our simulations, adsorption of atomic hydrogen on Al(111) surface leads to the formation of alanes via H-induced etching of aluminum atoms from the surface. The alanes then...

We report reactive dynamics (RD) studies on: the decomposition of bulk hydrazine (N(2)H(4)); the decomposition of bulk monomethyl-hydrazine (CH(3)N(2)H(3)), hereafter referred to simply as methyl-hydrazine; the decomposition of hydrazine in the presence of hydrogen peroxide (H(2)O(2)); and decomposition hydrazine on catalytic surfaces Pt[100] and Pt[111] under various conditions. These studies ...

We studied the thermal decomposition and subsequent reaction of the energetic material nitromethane (CH(3)NO(2)) using molecular dynamics with ReaxFF, a first principles-based reactive force field. We characterize the chemistry of liquid and solid nitromethane at high temperatures (2000-3000 K) and density 1.97 g/cm(3) for times up to 200 ps. At T = 3000 K the first reaction in the decompositio...

A scalable parallel algorithm has been designed to perform multimillion-atom molecular dynamics (MD) simulations, in which first principlesbased reactive force fields (ReaxFF) describe chemical reactions. Environment-dependent bond orders associated with atomic pairs and their derivatives are reused extensively with the aid of linked-list cells to minimize the computation associated with atomic...