Exploring the Chemical Space of Linear Alkane Pyrolysis via Deep Potential GENerator

Abstract

Reactive molecular dynamics (MD) simulation is a powerful tool to study the reaction mechanism of complex chemical systems. Central to the method is the potential energy surface (PES) that can describe the breaking and formation of chemical bonds. The development of PES of both accurate and efficent has attracted significant effort in the past two decades. Recently developed Deep Potential (DP) model has the promise to bring ab initio accuracy to large-scale reactive MD simulations. However, for complex chemical reaction processes like pyrolysis, it remains challenging to generate reliable DP models with an optimal training dataset. In this work, a dataset construction 1 scheme for such a purpose was established. The employment of a concurrent learning algorithm allows us to maximize the exploration of the chemical space while minimize the redundancy of the dataset. This greatly reduces the cost of computational resources required by ab initio calculations. Based on this method, we constructed a dataset for the pyrolysis of n-dodecane, which contains 35,496 structures. The reactive MD simulation with the DP model trained based on this dataset revealed the pyrolysis mechanism of n-dodecane in detail, and the simulation results are in good agreement with the experimental measurements. In addition, this dataset shows excellent transferability to different long-chain alkanes. These results demonstrate the advantages of the proposed method for constructing training datasets for similar systems.

Deep potentials for materials science

“…In the past three years, DPs have been applied in a number of systems in materials science including (1) elemental bulk systems, (2) multi-element bulk systems, (3) aqueous systems, (4) molecular systems and clusters, and ( 5) surfaces and lowdimensional systems. Table 2 shows a list of the material systems to which DPs have been applied (as of the writing of [187] Ice [188,189] Molecular systems and clusters Organic molecules [99,[190][191][192][193][194][195] Metal and alloy clusters [119,196] Surfaces and low-dimensional systems Metal and alloy surfaces [103,119,129] Graphane [125,197] Monolayer In 2 Se 3 [198] 2D Co-Fe-B [199] this paper). We choose several examples from each category to briefly discuss the corresponding DP application and how DP aids materials science research.…”

Deep Potentials for Materials Science

“…Jiang, et al [197] developed DPs for sulfuric acid-sulfuric acid, dimethylaminedimethylamine, and sulfuric aciddimethylamine organic molecular systems to investigate the atmospheric aerosol nucleation process. Zeng, et al [198] trained a DP based on a dataset for the pyrolysis of n-dodecane and performed a reactive DP MD simulation to reveal the detailed pyrolysis mechanism, in good agreement with experiment. Chen, et al [199] used a DP to accurately represent the ground-and excitedstate PES of CN 2 NH.…”

“…See [103] for details. [176] (Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)X (X=C or B2) [177,178] Aqueous Systems water [96,[179][180][181][182][183][184][185][186][187][188][189][190]] zinc ion in water [191] water-vapor interface [192,193] water-TiO2 interface [194] ice [195,196] Molecular Systems and Clusters organic molecules [101,[197][198][199][200][201][202]] metal and alloy clusters [126,203] Surfaces and Low-dimensional Systems metal and alloy surfaces [105,126,136] graphane [132,204] monolayer In2Se3…”

Growth of Polycyclic Aromatic Hydrocarbon and Soot Inception by in silico Simulation

“…These clusters were first classified according to the bond-type of the center atom and then the k-means clustering algorithm was used to remove the redundancy. Details of relevant methods can be found in our previous study (40,41). Finally, an initial dataset containing 1000 molecular clusters was obtained.…”

“…Recently, elementary reactions in the gas phase and on the surface have been studied using NNPES (32)(33)(34)(35)(36)(37)(38)(39). In our previous work, nanosecond-scale reactive MD simulations with NNPES were performed to explore detailed reaction network for methane combustion and pyrolysis of linear alkanes (40,41).…”