Electron-donating groups weaker than -NMe2, such as -OH, -OMe, -NH2, -Me and -NPH3 (Figure ) all exhibit inversions in the S1 state when placed at the R2 position, but the corresponding triplet of same configuration is not the T1 state. The only other R2 substituent we find which contributes to a negative S1-T1 gap at the EOM-CCSD level when used in conjunction with the -CN acceptor is the extremely strong alkylphosphazene (-NPMe3) donor (E(S1-T1)=-13 meV, see Figure for the full state diagram).