# A Shift Selection Strategy for Parallel Shift-Invert Spectrum Slicing in Symmetric Self-Consistent Eigenvalue Computation

## TL;DR

This paper introduces SISLICE, a parallel shift-invert eigenvalue algorithm that reduces communication costs and improves scalability for large symmetric eigenvalue problems, especially in scientific computations.

## Contribution

The paper presents a novel shift selection strategy for parallel shift-invert spectrum slicing, enhancing scalability and efficiency in large-scale eigenvalue computations.

## Key findings

- SISLICE significantly reduces communication overhead.
- The method demonstrates robust parallel performance.
- Effective shift selection improves eigenvalue problem solving.

## Abstract

The central importance of large scale eigenvalue problems in scientific computation necessitates the development of massively parallel algorithms for their solution. Recent advances in dense numerical linear algebra have enabled the routine treatment of eigenvalue problems with dimensions on the order of hundreds of thousands on the world's largest supercomputers. In cases where dense treatments are not feasible, Krylov subspace methods offer an attractive alternative due to the fact that they do not require storage of the problem matrices. However, demonstration of scalability of either of these classes of eigenvalue algorithms on computing architectures capable of expressing massive parallelism is non-trivial due to communication requirements and serial bottlenecks, respectively. In this work, we introduce the SISLICE method: a parallel shift-invert algorithm for the solution of the symmetric self-consistent field (SCF) eigenvalue problem. The SISLICE method drastically reduces the communication requirement of current parallel shift-invert eigenvalue algorithms through various shift selection and migration techniques based on density of states estimation and k-means clustering, respectively. This work demonstrates the robustness and parallel performance of the SISLICE method on a representative set of SCF eigenvalue problems and outlines research directions which will be explored in future work.

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Source: https://tomesphere.com/paper/1908.06043