We explored functionalization of calicene at various positions and with different substituents to evaluate the scope of the Hund's rule violation. The a2 occupied orbital has pronounced features on the carbon atoms of the 5-membered ring adjacent to the exocyclic double-bond (R2 position in Figure ), while the b2 occupied orbital does not. By placing electron-donating groups at the R2 position, the energy of the a2 HOMO is raised selectively relative to the b2 orbital. Substitution at the R3 position, however, destabilizes both occupied orbitals and in fact can eliminate the Hund's rule violation (e.g. E(S4-T4)=+65 meV for -OH substitution, Figure ). Substituting with donors at both available positions on the 5-membered ring preserves the Hund´s rule violation, but changes the order of the state state pair to S3-T4. Once an acceptor and donor have been placed at the R1 and R2 positions, respectively, further functionalization at the R3 position has no effect on either the magnitude or order of the violation. Reversal of the substituent strategy -by placing electron-donating groups on the 3-membered ring or electron-withdrawing groups on the 5-membered ring -also increases the state order of the Hund's rule violation or eliminates it entirely (Table ).