diff --git a/Project#14/README.md b/Project#14/README.md index 7d36425..58940f8 100644 --- a/Project#14/README.md +++ b/Project#14/README.md @@ -1 +1,25 @@ # Project #14: Excited Electronic States: EOM-CCSD + +Description of EOM-CCSD +An overview of the equation of motion coupled-cluster method is given in [1](#f1). + +## Step 1: Obtain CCSD T-amplitudes + +You require the converged T-amplitudes generated in [Project # 5](../Project%2305). You should also import the one- and two-electron components of the Hamiltonian. + +## Step 2: Create matrix elements of the similarity-transformed Hamiltonian + +The similarity-transformed Hamiltonian may be written as: + + + +in terms of sums over one-body, two-body and higher terms. These terms can then be found via the BCH expansion of the similarity-transformed Hamiltonian, in terms of converged T-amplitudes and one- and two-electron components of the Hamiltonian. A table of terms can be found in the paper by Stanton and Bartlett.[2](#f2) + +## Step 3: Diagonalize the similarity-transformed Hamiltonian + +## Bonus step: Left hand eigenvectors and oscillator strengths + +### References +1: Stanton, J. F.; Bartlett, R. J. "The Equation of Motion Coupled-Cluster Method. A Systematic Biorthogonal Approach to Molecular Excitation Energies, Transition Probabilities, and Excited State Properties." *J. Chem. Phys.* **10** , 981 (1993). [(return to text)](#r1) + +2: Zuev, D.; Vecharynski, E.; Yang, C.; Orms, N.; Krylov, A. I. "New Algorithms for Iterative Matrix-Free Eigensolvers in Quantum Chemistry." *J. Comput. Chem.* **36 (5)**, 273–284 (2015). [(return to text)](#r2) diff --git a/Project#14/figures/BCH_expansion.png b/Project#14/figures/BCH_expansion.png new file mode 100644 index 0000000..3ae19f6 Binary files /dev/null and b/Project#14/figures/BCH_expansion.png differ diff --git a/Project#14/figures/so_sim_trans_H.png b/Project#14/figures/so_sim_trans_H.png new file mode 100644 index 0000000..fdd7d5c Binary files /dev/null and b/Project#14/figures/so_sim_trans_H.png differ