recently identified an amine-substituted cyclopenta[c]pyrrole, however, we find its E(S 1 -T 2 ) to be +43 meV at the EOM-CCSD/aug-cc-pVDZ level. There are several substituted pyrrolo [3,4-c]pyrroles that exhibit Hund's rule violations between S 1 and T 2 , which are listed in Figure . The combination of larger substituents and reduced symmetry of the molecules hold great promise for design of molecules with increased oscillator strengths between S 1 and S 0 , which is essential for the molecules to be used as emitters.