Design and performance characterization of electronic structure calculations on massively parallel supercomputers: A case study of GPAW on the Blue Gene/P architecture

Density function theory (DFT) is the most widely employed electronic structure method because of its favorable scaling with system size and accuracy for a broad range of molecular and condensed-phase systems. The advent of massively parallel supercomputers has enhanced the scientific community's ability to study larger system sizes. Ground-state DFT calculations on∼10³ valence electrons using traditional O(N³) algorithms can be routinely performed on present-day supercomputers. The performance characteristics of these massively parallel DFT codes on>10⁴ computer cores are not well understood. The GPAW code was ported an optimized for the Blue Gene/P architecture. We present our algorithmic parallelization strategy and interpret the results for a number of benchmark test cases.