where T is a coupled-cluster excitation operator, Φ 0 is a reference determinant, and R is an excitation (EOM-EE-CCSD), spin-flip (EOM-SF-CCSD, EOM-DSF-CCSD), ionization (EOM-IP-CCSD, EOM-DIP-CCSD), or electron-attachment (EOM-EA-CCSD, EOM-DEA-CCSD) operator. EOM amplitudes R are obtained by diagonalization of the similarity-transformed Hamiltonian H in the basis of the determinants from the corresponding sector of the Fock space: