New implementation of high-level correlated methods using a general block tensor library for high-performance electronic structure calculations

• Published in: Journal of computational chemistry Vol. 34; no. 26; pp. 2293 - 2309
• Main Authors: Epifanovsky, Evgeny, Wormit, Michael, Kuś, Tomasz, Landau, Arie, Zuev, Dmitry, Khistyaev, Kirill, Manohar, Prashant, Kaliman, Ilya, Dreuw, Andreas, Krylov, Anna I.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 05.10.2013; Wiley Subscription Services, Inc
• Subjects: Algebra; Algorithms; coupled-cluster theory; electronic structure; Electrons; Object oriented programming; Open source software; quantum chemistry software; Symmetry; tensor algebra
• ISSN: 0192-8651; 1096-987X; 1096-987X
• DOI: 10.1002/jcc.23377

This article presents an open‐source object‐oriented C++ library of classes and routines to perform tensor algebra. The primary purpose of the library is to enable post‐Hartree–Fock electronic structure methods; however, the code is general enough to be applicable in other areas of physical and computational sciences. The library supports tensors of arbitrary order (dimensionality), size, and symmetry. Implemented data structures and algorithms operate on large tensors by splitting them into smaller blocks, storing them both in core memory and in files on disk, and applying divide‐and‐conquer‐type parallel algorithms to perform tensor algebra. The library offers a set of general tensor symmetry algorithms and a full implementation of tensor symmetries typically found in electronic structure theory: permutational, spin, and molecular point group symmetry. The Q‐Chem electronic structure software uses this library to drive coupled‐cluster, equation‐of‐motion, and algebraic‐diagrammatic construction methods. © 2013 Wiley Periodicals, Inc. The software library provides a programming interface and efficient parallel computational kernels to perform general block tensor algebra. The primary application is many‐body electronic structure methods, such as coupled‐cluster and equation‐of‐motion theories. The library specializes in computing very large tensors using divide‐and‐conquer algorithms, while utilizing the resources of just one compute node.