Left‐eigenstate completely renormalized equation‐of‐motion coupled‐cluster methods: Review of key concepts, extension to excited states of open‐shell systems, and comparison with electron‐attached and ionized approaches

Citations Over TimeTop 10% of 2009 papers

Abstract

Abstract The recently proposed left‐eigenstate completely renormalized (CR) coupled‐cluster (CC) method with singles, doubles, and noniterative triples, termed CR‐CC(2,3) Piecuch and Włoch, J Chem Phys, 2005, 123, 224105 ; Piecuch et al. Chem Phys Lett, 2006, 418, 467 and the companion CR‐EOMCC(2,3) methodology, which has been previously applied to singlet excited states of closed‐shell molecular systems Włoch et al. Mol Phys, 2006, 104, 2149 and in which relatively inexpensive noniterative corrections due to triple excitations derived from the biorthogonal method of moments of CC equations (MMCC) are added to the CC singles and doubles (CCSD) or equation‐of‐motion (EOM) CCSD energies, have been extended to excited states of open‐shell species. The resulting highly efficient computer codes for the open‐shell CR‐EOMCC(2,3) approach exploiting the recursively generated intermediates and fast matrix multiplication routines have been developed and interfaced with the GAMESS package, enabling CR‐EOMCC(2,3) calculations for singlet as well as nonsinglet ground and excited states of closed‐ and open‐shell systems using the restricted Hartree–Fock or restricted open‐shell Hartree–Fock references. A number of important mathematical and algorithmic details related to formal aspects and computer implementation of the CR‐EOMCC(2,3) method have been discussed, in addition to overviewing the key concepts behind the CR‐EOMCC(2,3) and biorthogonal MMCC methodologies for ground and excited states, and the numerical results involving low‐lying states of the CH, CNC, C 2 N, N 3 , and NCO species, including states dominated by two‐electron transitions, have been presented. The results of the CR‐EOMCC(2,3) calculations have been compared with other CC/EOMCC approaches, including the EOMCCSD and EOMCC singles, doubles, and triples methods, and their full and active‐space valence counterparts based on the electron‐attached and ionized EOMCC methodologies, and the predecessor of CR‐EOMCC(2,3) termed CR‐EOMCCSD(T) Kowalski and Piecuch, J Chem Phys, 2004, 120, 1715 . © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009

Related Papers

• → Extension of the Renormalized Coupled-Cluster Methods Exploiting Left Eigenstates of the Similarity-Transformed Hamiltonian to Open-Shell Systems: A Benchmark Study(2007)194 cited
• → Open-Shell Singlet Character of Stable Derivatives of Nonacene, Hexacene and Teranthene(2011)35 cited
• → Coupled-cluster method for open-shell heavy-element systems with spin-orbit coupling(2017)18 cited
• → Dipole moments of open-shell radicals using an analytic linear response approach in the Fock space multi-reference coupled cluster method(1999)21 cited
• → Computational Study of Electronic Properties in Oligoacenes(2022)