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
نویسندگان
چکیده
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 Correspondence to: P. Piecuch; e-mail: piecuch@chemistry.
منابع مشابه
Active-space symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster methods for high accuracy calculations of potential energy surfaces of radicals.
The electron-attached (EA) and ionized (IP) symmetry-adapted-cluster configuration-interaction (SAC-CI) methods and their equation-of-motion coupled-cluster (EOMCC) analogs provide an elegant framework for studying open-shell systems. As shown in this study, these schemes require the presence of higher-order excitations, such as the four-particle-three-hole (4p-3h) or four-hole-three-particle (...
متن کاملBreaking bonds of open-shell species with the restricted open-shell size extensive left eigenstate completely renormalized coupled-cluster method.
The recently developed restricted open-shell, size extensive, left eigenstate, completely renormalized (CR), coupled-cluster (CC) singles (S), doubles (D), and noniterative triples (T) approach, termed CR-CC(2,3) and abbreviated in this paper as ROCCL, is compared with the unrestricted CCSD(T) [UCCSD(T)] and multireference second-order perturbation theory (MRMP2) methods to assess the accuracy ...
متن کاملState Selective Equation of Motion Coupled Cluster Theory: Some Preliminary Results
A multireference variant of coupled cluster theory is described that applies to systems that can qualitatively be described by deleting two electrons from a closed shell determinant, for example biradicals, single bond breaking processes, or valence excited states. The theory can be generalized to arbitrary open-shell systems and takes a form that is akin to equation-of-motion coupled cluster t...
متن کاملDyson orbitals for ionization from the ground and electronically excited states within equation-of-motion coupled-cluster formalism: theory, implementation, and examples.
Implementation of Dyson orbitals for coupled-cluster and equation-of-motion coupled-cluster wave functions with single and double substitutions is described and demonstrated by examples. Both ionizations from the ground and electronically excited states are considered. Dyson orbitals are necessary for calculating electronic factors of angular distributions of photoelectrons, Compton profiles, e...
متن کاملThe X 1 S g + , B 1 D g , and B 8 1 S g + states of C 2 : A comparison of renormalized coupled - cluster and multireference methods with full configuration interaction benchmarks
Unusual bonding and electronic near degeneracies make the lowest-lying singlet states of the C2 molecule particularly challenging for electronic structure theory. Here we compare two alternative approaches to modeling bond-breaking reactions and excited states: sophisticated multireference configuration interaction and multireference perturbation theory methods, and a more “black box,” single-r...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2009