Projector-Augmented Wave-Based Kohn-Sham DFT with Reduced Order Scaling

Projector-Augmented Wave-Based Kohn-Sham DFT with Reduced Order Scaling

Presenter

  • Qi Li, IBM T.J. Watson Research Center, New York
September 13, 2017 - 11:00am to 12:00pm

Abstract 

In order to treat complex and large systems like metal-semiconductor heterostructures and DNA molecules, we developed an ab-initio molecular dynamics software OpenAtom, which is highly scalable on multi-petaflops parallel platforms. The plane-wave based Kohn-Sham Density Functional Theory (KS-DFT) computations in OpenAtom are currently performed using norm conserving nonlocal pseudopotentials, yielding a highly parallelize fast method. However, for many systems of interest, the Projector Augmented Wave (PAW) approach of Blochl has several important advantages, most notably (1) less demanding plane-wave cutoff energy due to the splitting of the KS states into delocalized and core parts and (2) direct access to the core-states if needed for NMR and other applications. However, traditional PAW based KS-DFT scales as N3 and the parallel performance is poor compared to the plane-wave approach. To solve this problem, we have developed a PAW based KS-DFT with N2logN scaling enabled by Euler Exponential Spline (EES) and FFTs to form a 4 grid multi-resolution method . We have also increased the accuracy of the long range interactions by applying Ewald summation methods to the Hartree and electron-ion external energies. Our development, as implemented in OpenAtom, inherits all the merits of the PAW method with significantly higher parallel and scalar efficiency.

Sponsoring Organization 

Materials Science and Technology Division Materials Theory Group Seminar

Location

  • Chemical and Materials Sciences Building
  • Building: 4100
  • Room: J-302

Contact Information

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