About

BerkeleyGW is a many-body perturbation theory code for excited states, using the GW method and the GW plus Bethe-Salpeter equation (GW-BSE) method to solve respectively for quasiparticle excitations and optical properties of materials. It is suitable for 3D, 2D, 1D, and molecular systems. It can be applied to insulating, metallic, and semi-metallic systems. BerkeleyGW is massively parallelized with MPI, OpenMP, SIMD, and we have recently ported it to GPUs, reaching 86x speedup compared to the CPU implementation.

The latest BerkeleyGW can be applied to study systems up to a few thousand atoms. A recent calculation of GW quasiparticle excitation energies of divacancies in Si and SiC adopts a supercell contains > 2700 atoms (> 10,000 electrons), reaching 105.9 double-precision PetaFLOP/s, 52.7% of the peak performance, running at full-scale of Summit at OLCF with 27,648 GPUs. The GPU version of BerkeleyGW will be released soon!

si2742

The BerkeleyGW package takes the DFT wavefunctions and eigenvalues as input files. BerkeleyGW currently supports the following DFT codes with proper wrappers:

The package consists of the three main component codes:

  • Epsilon computes the irreducible polarizability in the Random Phase Approximation and uses it to generate the dielectric matrix and its inverse.
  • Sigma computes the self-energy corrections to the DFT eigenenergies using the GW approximation of Hedin and Lundqvist, applying the first-principles methodology of Hybertsen and Louie within the generalized plasmon-pole model for the frequency-dependent dielectric matrix.
  • BSE solves the Bethe-Salpeter equation for correlated electron-hole excitations.

When using BerkeleyGW, you are expected to cite the following papers and acknowledge the use of the BerkeleyGW package in your publications.

  • [1] Mark S. Hybertsen and Steven G. Louie, “Electron correlation in semiconductors and insulators: Band gaps and quasiparticle energies,” Phys. Rev. B 34, 5390 (1986)
  • [2] Michael Rohlfing and Steven G. Louie, “Electron-hole excitations and optical spectra from first principles,” Phys. Rev. B 62, 4927 (2000)

Papers [1] and [3] should be cited when discussing quasiparticle properties such as GW band structures, and papers [2] and [3] should be cited when discussing optical properties with excitonic effects.

BerkeleyGW is currently supported by the Center for Computational Study of Excited-State Phenomena in Energy Materials (C2SEPEM) at Lawrence Berkeley National Laboratory. C2SEPEM currently support another two excited-state codes: StochasticGW which utilizes the stochastic sampling technique and reaches linear scaling in system size, and NanoGW which is based on the solution of the Casida equation employing a real-space basis.