A partitioned shift-without-invert algorithm to improve parallel eigensolution efficiency in real-space electronic transport

作者：Feldman Baruch^*; Zhou Yunkai

来源：Computer Physics Communications, 2016, 207: 105-113.

DOI：10.1016/j.cpc.2016.05.015

• Eigensolution
• Electronic structure
• Electronic transport
• High-performance computing
• Parallel computing
• Shift-invert

We present an eigenspectrum partitioning scheme without inversion for the recently described real space electronic transport code, TRANSEC. The primary advantage of TRANSEC is its highly parallel algorithm, which enables studying conductance in large systems. The present scheme adds a new source of parallelization, significantly enhancing TRANSEC's parallel scalability, especially for systems with many electrons. In principle, partitioning could enable super-linear parallel speedup, as we demonstrate in calculations within TRANSEC. In practical cases, we report better than five-fold improvement in CPU time and similar improvements in wall time, compared to previously-published large calculations. Importantly, the suggested scheme is relatively simple to implement. It can be useful for general large Hermitian or weakly non-Hermitian eigenvalue problems, whenever relatively accurate inversion via direct or iterative linear solvers is impractical.

• 出版日期2016-10