Implementation of Relativistic Coupled Cluster Theory for Massively Parallel GPU-Accelerated Computing Architectures

• Published in: Journal of chemical theory and computation Vol. 17; no. 9; pp. 5509 - 5529
• Main Authors: Pototschnig, Johann V, Papadopoulos, Anastasios, Lyakh, Dmitry I, Repisky, Michal, Halbert, Loïc, Severo Pereira Gomes, André, Jensen, Hans Jørgen Aa, Visscher, Lucas
• Format: Journal Article
• Language: English
• Published: Washington American Chemical Society 14.09.2021
• Subjects: Algorithms; Chemical Physics; Chemical Sciences; Clusters; Coupling (molecular); Electronic structure; Heavy elements; Modules; Molecular orbitals; or physical chemistry; Physics; Quantum Electronic Structure; Relativistic effects; Relativistic theory; Self consistent fields; Theoretical and
• ISSN: 1549-9618; 1549-9626; 1549-9626
• DOI: 10.1021/acs.jctc.1c00260

In this paper, we report reimplementation of the core algorithms of relativistic coupled cluster theory aimed at modern heterogeneous high-performance computational infrastructures. The code is designed for parallel execution on many compute nodes with optional GPU coprocessing, accomplished via the new ExaTENSOR back end. The resulting ExaCorr module is primarily intended for calculations of molecules with one or more heavy elements, as relativistic effects on the electronic structure are included from the outset. In the current work, we thereby focus on exact two-component methods and demonstrate the accuracy and performance of the software. The module can be used as a stand-alone program requiring a set of molecular orbital coefficients as the starting point, but it is also interfaced to the DIRAC program that can be used to generate these. We therefore also briefly discuss an improvement of the parallel computing aspects of the relativistic self-consistent field algorithm of the DIRAC program.