BerkeleyGW: A Massively Parallel Computer Package for the Calculation of   the Quasiparticle and Optical Properties of Materials and Nanostructures
  BerkeleyGW is a massively parallel computational package for electron excited-state properties that is based on the many-body perturbation theory employing the ab initio GW and GW plus Bethe-Salpeter equation methodology. It can be used in conjunction with many density-functional theory codes for ground-state properties, including PARATEC, PARSEC, Quantum ESPRESSO, OCTOPUS and SIESTA. The package can be used to compute the electronic and optical properties of a wide variety of material systems from bulk semiconductors and metals to nanostructured materials and molecules. The package scales to 10,000's of CPUs and can be used to study systems containing up to 100's of atoms. 
Jack Deslippe, Georgy Samsonidze, David A. Strubbe, Manish Jain,   Marvin L. Cohen, Steven G. Louie
cond-mat.mtrl-sci