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Excitonic Coupled-cluster Theory: Part I, General Formalism.pdf (528.45 kB)
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Excitonic Coupled-cluster Theory: Part I, General Formalism

preprint
revised on 27.08.2017 and posted on 28.08.2017 by Yuhong Liu, Anthony Dutoi
A shortcoming of presently available fragment-based methods is that electron correlation (if included) is described at the level of individual electrons, resulting in many redundant evaluations of the electronic relaxations associated with any given fluctuation. A generalized variant of coupled-cluster (CC) theory is described, wherein the degrees of freedom are fluctuations of fragments between internally correlated states. The effects of intra-fragment correlation on the inter-fragment interaction is pre-computed and permanently folded into the effective Hamiltonian. This article provides a high-level description of the CC variant, establishing some useful notation, and it demonstrates the advantage of the proposed paradigm numerically on model systems. A companion article shows that the electronic Hamiltonian of real systems may always be cast in the form demanded. This framework opens a promising path to build finely tunable systematically improvable methods to capture precise properties of systems interacting with a large number of other systems.

Funding

University of the Pacific start-up (Hornage Fund)

History

Topic

  • Theory

Email Address of Submitting Author

adutoi@pacific.edu

Email Address(es) for Other Author(s)

yliu3@pacific.edu

Institution

University of the Pacific

Country

USA

ORCID For Submitting Author

0000-0001-6899-4345

Declaration of Conflict of Interest

No conflict of interest.

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