The EOM operator, R, has the form that depends on a particular flavor of EOM (as illustrated in Fig. ). We use EOM-CC methods that are best suited for each type of electronic states studied here • EOM-EA-CCSD . In this method the Hartree-Fock reference corresponds to a closed-shell cation and the EOM operator R has one more creation than annihilation operators, giving rise to the EOM-EA-CCSD wave-functions of the neutral states. This method is suitable for CaOH and pAB.