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Title: Approximating electronically excited states with equation-of-motion linear coupled-cluster theory

A new perturbative approach to canonical equation-of-motion coupled-cluster theory is presented using coupled-cluster perturbation theory. A second-order Møller-Plesset partitioning of the Hamiltonian is used to obtain the well known equation-of-motion many-body perturbation theory equations and two new equation-of-motion methods based on the linear coupled-cluster doubles and linear coupled-cluster singles and doubles wavefunctions. These new methods are benchmarked against very accurate theoretical and experimental spectra from 25 small organic molecules. It is found that the proposed methods have excellent agreement with canonical equation-of-motion coupled-cluster singles and doubles state for state orderings and relative excited state energies as well as acceptable quantitative agreement for absolute excitation energies compared with the best estimate theory and experimental spectra.
Authors:
; ;  [1] ;  [1] ;  [2]
  1. Quantum Theory Project, University of Florida, Gainesville, Florida 32611 (United States)
  2. (Germany)
Publication Date:
OSTI Identifier:
22493142
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 97 MATHEMATICAL METHODS AND COMPUTING; APPROXIMATIONS; COMPARATIVE EVALUATIONS; EQUATIONS OF MOTION; EXCITATION; EXCITED STATES; HAMILTONIANS; MANY-BODY PROBLEM; MOLECULES; PERTURBATION THEORY; SPECTRA; WAVE FUNCTIONS