✦ LIBER ✦

On multiple solutions of the Fock-space coupled-cluster method

✍ Scribed by Leszek Meissner

Publisher: Elsevier Science
Year: 1996
Tongue: English
Weight: 534 KB
Volume: 255
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(96)00400-9

No coin nor oath required. For personal study only.

✦ Synopsis

Intermediate Hamiltonian techniques are used to investigate the problem of multiple solutions of the Fock-space coupled-cluster methods. Two intermediate Hamiitonian schemes are presented, based upon similarity transformations that unlike the wave operator formalism allow for following the complete eigenvalue problem. Solutions of the standard effective Hamiltonian formulation that requires iterative approaches to solve the equations are equivalently given by diagonalization of the intermediate Hamiltonian matrix representations. This procedure provides a systematic way of obtaining all possible solutions of the effective Hamiltonian scheme in all sectors higher than the lowest one.

📜 SIMILAR VOLUMES

High sectors in the Fock space coupled-c

High sectors in the Fock space coupled-cluster method

✍ S.R. Hughes; Uzi Kaldor 📂 Article 📅 1992 🏛 Elsevier Science 🌐 English ⚖ 437 KB

Multiple solutions of the single-referen

Multiple solutions of the single-reference coupled-cluster method

✍ Leszek Meissner; Anna Balková; Rodney J. Bartlett 📂 Article 📅 1993 🏛 Elsevier Science 🌐 English ⚖ 696 KB

The nonlinear coupled-cluster (CC) equations possess several solutions. They describe various excited states as long as they contain a contribution from the reference function. We study the additional solutions of the single-reference CC equations and demonstrate that unlike the ground state, the ap

Complete active space coupled-cluster me

Complete active space coupled-cluster method. Extension of single-reference coupled-cluster method using the CASSCF wavefunction

✍ Leszek Z. Stolarczyk 📂 Article 📅 1994 🏛 Elsevier Science 🌐 English ⚖ 471 KB

It is proposed that the calculation of non-dynamical electronic correlation effects by the complete active space self-consistent field (CASSCF) method can be extended by the inclusion of dynamical correlation effects through the use of a suitably modified single-reference coupled-cluster (CC) proced

The coupled-cluster method with full inc

The coupled-cluster method with full inclusion of single, double and triple excitations applied to high sectors of the Fock space

✍ S.R. Hughes; Uzi Kaldor 📂 Article 📅 1993 🏛 Elsevier Science 🌐 English ⚖ 370 KB

The coupled-cluster method with singte, double and triple excitations (CCSDT or SUB3) is applied to a system with up to six electrons outside a closed shell. The Ne atom and its ions serve as a test case. Starting from Ne\*+, electrons are added one at a time ah the way to Ne. Ionization potentials

Application of the valence-universal cou

Application of the valence-universal coupled-cluster method based on various model spaces. II. Nonstandard solutions for Be

✍ K. Jankowski; P. Malinowski 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 836 KB

The impact of the choices of the complete model space (CMS) and of the orbital basis set on the existence, attainability, and properties of the nonstandard solutions of the valence-universal coupled-cluster (VU-CC) methods has been studied for the case of nonlinear equations corresponding to the ato

On the Easy Generation of the Diagrams R

On the Easy Generation of the Diagrams Representing the Coupled Cluster Method

✍ S.R. Hughes; Uzi Kaldor 📂 Article 📅 1993 🏛 Elsevier Science 🌐 English ⚖ 311 KB