We assess the validity of different EOM models by comparing them with each other. As expected, EOM-SF and EOM-DIP yields similar results, while EOM-EE produces a different state ordering. EOM-SF treats the determinants of the target 1 A states in a balanced manner (in this case the occupation of orbitals is approximately the same as in the reference triplet). However, in the target 1 A states the treatment of leading determinants is unbalanced: from 3 A reference determinant ( ) is generated by a single excitation, whereas its spin-complete partner (5) cannot be obtained by a single excitation; the same is true for the 1 A reference and determinants ( ) and (7). The wavefunctions of these A states are severely spin-contaminated, with S 2 close to 1. The PES (discussed in Section 4.1 and in SI) of this state lies in between singlet and triplet states from the EOM-DIP calculation, giving an averaged description.