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arXiv · 2110.14362

A random batch Ewald method for charged particles in the isothermal-isobaric ensemble

Jiuyang Liang·Pan Tan·Liang Hong·Shi Jin·Zhenli Xu·Lei Li
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Abstract

We develop an accurate, highly efficient and scalable random batch Ewald (RBE) method to conduct simulations in the isothermal-isobaric ensemble (the NPT ensemble) for charged particles in a periodic box. After discretizing the Langevin equations of motion derived using suitable Lagrangians, the RBE method builds the mini-batch strategy into the Fourier space in the Ewald summation for the pressure and forces so the computational cost is reduced from $\mathcal{O}(N^2)$ to $\mathcal{O}(N)$ per time step. We implement the method in the LAMMPS package and report accurate simulation results for both dynamical quantities and statistics for equilibrium for typical systems including all-atom bulk water and a semi-isotropic membrane system. Numerical simulations on massive supercomputing cluster are also performed to show promising CPU efficiency of RBE.

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Jiuyang Liang, Pan Tan, Liang Hong, Shi Jin, Zhenli Xu, Lei Li. 2021-10-27. A random batch Ewald method for charged particles in the isothermal-isobaric ensemble. https://doi.org/10.1063/5.0107140

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