**I. Electronically excited states**

a) configuration interaction singles (CIS) approaches

CIS, also known as Tamm-Dancoff approximation (TDA))

`I. Tamm, J. Phys. USSR 9, 449 (1945)`

`S.M. Dancoff, Non-adiabatic meson theory of nuclear forces, Phys. Rev. 78, 382 (1950)`

`J.B. Foresman, M. Head-Gordon, J.A. Pople, and M.J. Frisch, Toward a systematic molecular orbital theory for excited states, J. Phys. Chem. 96, 135-149 (1992)`

CIS plus a perturbative corrections for doubles (CIS(D))

`M. Head-Gordon, R.J. Rico, M. Oumi, and T.J. Lee, A doubles correction to electronic excited states from configuration interaction in the space of single substitutions, Chem. Phys. Letters 219, 21-29 (1994)`

CIS(D) gradients

`J.F. Stanton, J. Gauss, N. Ishikawa, and M. Head-Gordon, A comparison of single reference methods for characterizing stationary points of excited state potential energy surfaces, J. Chem. Phys. 103, 4160 (1995)`

b) via coupled-cluster linear response (CC_LR) theory

review on CC response theory

`O. Christiansen, C. Hättig, and P. Jørgensen, Response functions from Fourier component variational perturbation theory applied to a time‐averaged quasienergy, Int. J. Quantum Chem. 68, 1-52 (1998)`

CC linear response theory

`H.J. Monkhorst, Calculation of properties with the coupled‐cluster method, Int. J. Quant. Chem. Symp. 11, 421-432 (1977)`

`H. Koch and P. Jørgensen, Coupled cluster response functions, J. Chem. Phys. 93, 3333 (1990)`

CCSD-LR

`H. Koch, H.J.Aa. Jensen, P. Jørgensen and T. Helgaker, Excitation energies from the coupled cluster singles and doubles linear response function (CCSDLR). Applications to Be, CH+, CO, and H2O, J. Chem. Phys. 93, 3345 (1990)`

CC3-LR

`O. Christiansen, H. Koch, and P. Jørgensen, Response functions in the CC3 iterative triple excitation model, J. Chem. Phys. 103, 7429 (1995)`

CC-LR for general CC models

`M. Kállay and J. Gauss, Calculation of excited-state properties using general coupled-cluster and configuration-interaction models, J. Chem. Phys. 121, 9257 (2004)`

CC-LR for Mk-MRCC theory

`T.-C. Jagau and J. Gauss, Linear-response theory for Mukherjee's multireference coupled-cluster method: Excitation energies, J. Chem. Phys. 137, 044116 (2012)`

c) via an equation-of-motion coupled-cluster (EOM-CC) ansatz

EOM-CCSD

`J.F. Stanton and R.J. Bartlett, 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 (1993)`

EOM-CCSDT

`K. Kowalski and P. Piecuch, The active-space equation-of-motion coupled-cluster methods for excited electronic states: Full EOMCCSDt, J. Chem. Phys. 115, 643 (2001) `

`S.A. Kucharski, M. Wloch, M. Musial, and R.J. Bartlett, Coupled-cluster theory for excited electronic states: The full equation-of-motion coupled-cluster single, double, and triple excitation method, J. Chem. Phys. 115, 8263 (2001)`

`Y. Bomble, K.W. Sattelmeyer, J.F. Stanton, and J. Gauss, On the vertical excitation energy of cyclopentadiene, J. Chem. Phys. 121, 5236 (2004); present implementation within Cfour`

EOM for general CC models

`M. Kállay and J. Gauss, Calculation of excited-state properties using general coupled-cluster and configuration-interaction models, J. Chem. Phys. 121, 9257 (2004)`

c) property calculations in CC-LR/EOM-CC

analytic gradients for EOM-CCSD/CCSD-LR

`J.F. Stanton, 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 (1993) (theory) `

`J.F. Stanton and J. Gauss, Analytic energy gradients for the equation‐of‐motion coupled‐cluster method: Implementation and application to the HCN/HNC system, J. Chem. Phys. 100, 4695 (1994) (implementation)`

`J.F. Stanton and J. Gauss, Analytic energy derivatives for the equation-of-motion coupled-cluster method: Algebraic expressions, implementation and application to theS 1 state of HFCO, Theor. Chim. Acta 91, 267-289 (1995) (implementation)`

analytic gradients for general EOM-CC/CC-LR

`M. Kállay and J. Gauss, Calculation of excited-state properties using general coupled-cluster and configuration-interaction models, J. Chem. Phys. 121, 9257 (2004)`

**II. Ionized states**

EOMIP-CCSD

`J.F. Stanton and J. Gauss, Analytic energy derivatives for ionized states described by the equation‐of‐motion coupled cluster method, J. Chem. Phys. 101, 8938 (1994)`

EOMIP-CC3 and EOMIP-CCSDT-n

`J.F. Stanton and J. Gauss, A simple scheme for the direct calculation of ionization potentials with coupled-cluster theory that exploits established excitation energy methods, J. Chem. Phys. 111, 8785 (1999)`

EOMIP-CCSD(2)

`J.F. Stanton and J. Gauss, Perturbative treatment of the similarity transformed Hamiltonian in equation‐of‐motion coupled‐cluster approximations, J. Chem. Phys.103, 1064 (1995)`

analytic gradients for EOMIP-CCSD

`J.F. Stanton and J. Gauss, Analytic energy derivatives for ionized states described by the equation‐of‐motion coupled cluster method, J. Chem. Phys. 101, 8938 (1994)`

**III. Electron-attached states**

EOMEA-CCSD

`M. Nooijen and R.J. Bartlett, Equation of motion coupled cluster method for electron attachment, J. Chem. Phys. 102, 3629 (1996)`

analytic gradients for EOMEA-CCSD

`J.F. Stanton and J. Gauss, unpublished`