The 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... 

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. 

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. 

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. 

Watts, J.D., Bartlett, R.J. The inclusion of connected triple excitations in the equation-of-motion coupled-cluster method. J. Chem. Phys. 1994,101(4), 3073-78. 

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

D. C. Comeau and R. J. Bartlett, Chem. Phys. Lett., 207, 414 (1993). The Equation-of-Motion Coupled-Cluster Method Applications to Open- and Closed-Shell Reference States. 

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