TY - JOUR

T1 - Petascale Orbital-Free Density Functional Theory Enabled by Small-Box Algorithms

AU - Chen, Mohan

AU - Jiang, Xiang Wei

AU - Zhuang, Houlong

AU - Wang, Lin Wang

AU - Carter, Emily A.

N1 - Funding Information:
This work was supported by the Office of Naval Research (Grant N00014-15-1-2218 to E.A.C. and L.-W.W.). L.-W.W. is primarily supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the U.S. Department of Energy (DOE) under Contract No. DEAC02-05CH11231 through the Material Theory Program (KC2301) at LBNL. The authors thank Ms. Nari Baughman and Dr. Johannes M. Dieterich for helping to edit this manuscript. The authors thank the Terascale Infrastructure for Groundbreaking Research in Science and Engineering (TIGRESS) high performance computing center at Princeton University and the Garnet supercomputer at the DoD Supercomputing Resource Center (DSRC). The research also used computational resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the DOE under Contract No. DE-AC05-000R22725, with computational time allocated by the Innovative and Novel Computational Impact on Theory and Experiment Project.
Publisher Copyright:
© 2016 American Chemical Society.

PY - 2016/6/14

Y1 - 2016/6/14

N2 - Orbital-free density functional theory (OFDFT) is a quantum-mechanics-based method that utilizes electron density as its sole variable. The main computational cost in OFDFT is the ubiquitous use of the fast Fourier transform (FFT), which is mainly adopted to evaluate the kinetic energy density functional (KEDF) and electron-electron Coulomb interaction terms. We design and implement a small-box FFT (SBFFT) algorithm to overcome the parallelization limitations of conventional FFT algorithms. We also propose real-space truncation of the nonlocal Wang-Teter KEDF kernel. The scalability of the SBFFT is demonstrated by efficiently simulating one full optimization step (electron density, energies, forces, and stresses) of 1,024,000 lithium (Li) atoms on up to 65,536 cores. We perform other tests using Li as a test material, including calculations of physical properties of different phases of bulk Li, geometry optimizations of nanocrystalline Li, and molecular dynamics simulations of liquid Li. All of the tests yield excellent agreement with the original OFDFT results, suggesting that the OFDFT-SBFFT algorithm opens the door to efficient first-principles simulations of materials containing millions of atoms.

AB - Orbital-free density functional theory (OFDFT) is a quantum-mechanics-based method that utilizes electron density as its sole variable. The main computational cost in OFDFT is the ubiquitous use of the fast Fourier transform (FFT), which is mainly adopted to evaluate the kinetic energy density functional (KEDF) and electron-electron Coulomb interaction terms. We design and implement a small-box FFT (SBFFT) algorithm to overcome the parallelization limitations of conventional FFT algorithms. We also propose real-space truncation of the nonlocal Wang-Teter KEDF kernel. The scalability of the SBFFT is demonstrated by efficiently simulating one full optimization step (electron density, energies, forces, and stresses) of 1,024,000 lithium (Li) atoms on up to 65,536 cores. We perform other tests using Li as a test material, including calculations of physical properties of different phases of bulk Li, geometry optimizations of nanocrystalline Li, and molecular dynamics simulations of liquid Li. All of the tests yield excellent agreement with the original OFDFT results, suggesting that the OFDFT-SBFFT algorithm opens the door to efficient first-principles simulations of materials containing millions of atoms.

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U2 - 10.1021/acs.jctc.6b00326

DO - 10.1021/acs.jctc.6b00326

M3 - Article

C2 - 27145175

AN - SCOPUS:84974816793

SN - 1549-9618

VL - 12

SP - 2950

EP - 2963

JO - Journal of Chemical Theory and Computation

JF - Journal of Chemical Theory and Computation

IS - 6

ER -