Linear-scaling density-functional-theory calculations of electronic structure based on real-space grids: design, analysis, and scalability test of parallel algorithms

We have implemented parallel algorithms for density-functional-theory (DFT) based electronic-structure calculations. These include a plane-wave based algorithm, a real-space-grid algorithm based on a high-order finite differe nce method, and a linear-scaling real-space algorithm using localized orbit als. Parallelization schemes are described for these algorithms, and the co mputational complexity and the communications involved in the resulting par allel algorithms are analyzed. Scalability tests of these algorithms on mas sively parallel computers show that the linear-scaling DFT algorithm is hig hly scalable. For a 110,592-atom gallium arsenide system on 1024 IBM SP3 pr ocessors, the parallel efficiency is as high as 93%. (C) 2001 Elsevier Scie nce B.V. All rights reserved.