The optimized ground-state geometry and energy levels of 2,7-tBuCzNB were calculated using Density Functional Theory (DFT) at the PBE0/6-31G(d,p) level (Figure ), starting from a structure drawn and optimized using Chem3D. The lowest unoccupied molecular orbital (LUMO) is localized on the Cz-SCz core. The calculated LUMO level of -1.87 eV is slightly more stabilized than that of Cz-SCz (-1.68 eV) (Figure ). The highest occupied molecular orbital (HOMO) is distributed on the peripheral twisted second-generation carbazole donor dendron due to its strong electron-donating character. The calculated HOMO energy of 2,7-tBuCzNB is -5.18 eV, which is close to that of 2GCzBP (HOMO of -5.19 eV) and 2GCzBPN (HOMO of -5.25 eV), both containing a regioisomeric second-generation carbazole donor dendron. The different regiochemistry of the peripheral tert-carbazole groups does not have a significant effect on the energy level. The excited-state energies were first calculated using time-dependent DFT within the Tamm-Dancoff approximation (TDA-DFT) at the PBE0/6-31G(d,p) level (Figure ). The S1 state and the lowest triplet state (T1) energies Spin-Component Scaling second-order algebraic diagrammatic construction (SCS-(ADC)2/cc-pVDZ) calculations provide more accurate predictions of the excited-state energies and difference densities in MR-TADF compounds than TD-DFT methods (Figure ). The alternating difference density patterns for both the S1 and T1 states are localized on the Cz-SCz core, indicating that these states have SRCT character. The S1/T1 energies are calculated to be 2.95/2.80 eV and the corresponding DEST value is 0.15 eV. Both the difference densities and the small DEST indicate the likelihood of 2,7-tBuCzNB to be a MR-TADF emitter.