states of both MeCzCO2HDCzB and 2GMeCzCO2HDCzB are primarily located on the DCzB core and show the characteristic alternating pattern of increasing and decreasing electron density in the excited states compared to the ground state that describes a short-range charge transfer (SRCT) excited state (Figure ). The NTOs of the closely lying T2 states is distributed across on the central benzene ring of the MR-TADF core and the benzoate, and that of T3 is localized on the carbazole of the MR-TADF core of MeCzCO2HDCzB and has LRCT character for 2GMeCzCO2HDCzB. The spin-orbital coupling matrix element (SOCME) between S1, and T1, performed based on the T1 state geometry, are 0.135 and 0.087 cm -1 for 2GMeCzCO2HDCzB and MeCzCO2HDCzB , respectively, while those between two closelying triplet states and S1 are generally much larger at 0.609 and 0.213 cm -1 for 2GMeCzCNDCzB and 0.693 and 0.133 cm -1 for MeCzCO2HDCzB , indicating a RISC mechanism that is likely to occur via spin-vibronic coupling involving one or more these states. To substantiate the emitter design, we modelled two fragments of the parent emitters, 2GMeCzCO2H and MeCzCO2H (Figure ), emulating the D-A part of the compounds. This was done to verify whether their energy levels were higher than those of the MR-TADF core, DMeCzB, such that energy transfer between the two fragments would be possible.