Equation-of-motion coupled-cluster method

Stanton JF, Bartlett RJ (1993) The equation of motion coupled-cluster method - a systematic biorthogonal approach to molecular-excitation energies, transition-probabilities, and excited-state properties. J Chem Phys 98 7029... 

Hirata, S. Higher-order equation-of-motion coupled-cluster methods. J. Chem. Phys. 2004, 121, 51-9. 

BASIC ELEMENTS OF COUPLED-CLUSTER AND EQUATION-OF-MOTION COUPLED-CLUSTER METHODS... 

Inclusion of connected triple excitations in the equation-of-motion coupled-cluster method for calculating excitation energies was also tested on SiFP230. Excitation energies predicted for the lowest triplet state and the two lowest excited singlet states 1 Si and 2 lAi were within a kcal mol 1 of the predictions of the full Cl calculation when triple excitations were included, but only for the 2 3Ai state was there marked improvement over the inclusion of only single and double excitations. 

J. Geersten, M. Rittby, R.J. Bartlett, The equation-of-motion coupled-cluster method Excitation energies of Be and CO, Chem. Phys. Lett. 164 (1989) 57 D.C. Comeau, R.J. Bartlett, The equation-of-motion coupled-cluster method. Applications to open- and closed-shell reference states, Chem. Phys. Lett. 207 (1993) 414. 

More demanding calculations conducted by Daniel et al. using equations-of-motion coupled cluster methods (EOM-CC) provided a better description of the contribution of MLCT andMC transitions to the electronic spectrum of Cr(CO)6 [13]. These calculations confirm that the lowest-energy transition, which is responsible for the shoulder on the low-energy side of the first absorption maximum, corresponds to... 

Watts JD, Bartlett RJ (1995) Economical triple excitation equation-of-motion coupled-cluster methods for excitation energies. Chem Phys Lett 233 81-87. 

Kowalski K, Piecuch P (2000) The active-space equation-of-motion coupled-cluster methods for excited states The EOMCCSDt approach. J Chem Phys 113 8490-8502. 

Stanton JF (1993) Many-body methods for excited state potential energy surfaces I. General theory of energy gradients for the equation-of-motion coupled-cluster method. J Chem Phys 99 8840-8847. 

L. Meissner and R. J. Bartlett, J. Chem. Phys., 94, 6670 (1991). Transformation of the Hamiltonian in Excitation Energy Calculations Comparison Between Fock-Space Multireference Coupled-Cluster and Equation-of-Motion Coupled-Cluster Methods. 

State Potential Energy Surfaces. I. General Theory of Energy Gradients for the Equation-of-Motion Coupled-Cluster Method. 

J. F. Stanton and J. Gauss,/. Chem. Phys., 101,8938 (1994). Analytic Energy Derivatives fot Ionized States Described hy the Equation-of-Motion Coupled-Cluster Method. 

Approximate Inclusion of the and Operators in the Equation-of-motion Coupled-cluster Method... 

Kiylov, A I. (2008). Equation-of-Motion Coupled-Cluster Methods for Open-Shell and Electronically Excited Species The fJitchhiker s Guide to Fock Space, Annu. Rev. Phys. Chem., 59,433-462. 

Abstract The singlet-triplet splittings of the di-radicals methylene, trimethylene-methane, ortha-, meta- and para-benzynes, and cyclobutane-l,2,3,4-tetrone have become test systems for the applications of various multi-reference (MR) coupled-cluster methods. We report results close to the basis set limit computed with double ionization potential (DIP) and double electron attachment (DBA) equation-of-motion coupled-cluster methods. These diradicals share the characteristics of a 2-hole 2-particle MR problem and are commonly used to assess the performance of MR methods, and yet require more careful study unto themselves as benchmarks. Here, using our CCSD(T)/6-311G(2d,2p) optimized geometries, we report DIP/DEA-CC results and single-reference (SR) CCSD, CCSD(T), ACCSD(T) and CCSDT results for comparison. 

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