Reactive force field (ReaxFF)1 is a bond-order potential and allows for reactive molecular dynamics (ReaxFF MD) simulations for larger and more complex systems involving chemical reactions compared with DFT. GMD-Reax2, the first GPU-enabled ReaxFF MD program with significantly improved performance surpassing CPU implementations on desktop workstations, was developed and has been used to explore the initial chemical mechanisms and product distributions in pyrolysis of large scale coal models including a complex bituminous Liulin coal model with 28,351 atoms3, the second largest ever used in ReaxFF MD. The simulations at 1000-2600 K were performed using GMD-Reax for 250 ps to investigate the temperature effects on the Liulin coal pyrolysis and the simulation results are in broad agreement with experimentations in literature. This work demonstrated GMD-Reax as an very efficient computational tool to meet the challenges in coal pyrolysis mechanism investigation on desktop workstations and will assist for a profound understanding of the complex chemical reactions occurred in large scale molecular systems.Table 1. Performance of GMD-Reax (a NVIDIA C2050 GPU) and LAMMPS reax on CPUs (Intel Xeon E5620 2.4 GHz) Acknowledgements This work was supported by the National Natural Science Foundation of China [21073195, 21373227] and China's State Key Laboratory of Multiphase Complex Systems [MPCS-2012-A-05].References 1.    van Duin, A. C. T.; Dasgupta, S.; Lorant, F.; Goddard, W. A., J. Phys. Chem. A 2001,  105 (41), 9396-9409.2.    Zheng, M.; Li, X.; Guo, L., J. Mol. Graphics Modell. 2013,  41, 1-11.3.    Zheng, M. et al. Energy Fuels 2014,  28 (1), 522-534.

GPU-enabled reactive force field (ReaxFF) molecular dynamics for large scale simulation of Liulin coal pyrolysis

248th National Meeting (2014)

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