Addressing the High-Throughput Screening Challenges of Inverted Singlet–Triplet Materials by MRSF-TDDFT

A new computational protocol utilizing mixed-reference spin-flip time-dependent density functional theory (MRSF-TDDFT) and the DTCAM-STG exchange-correlation functional has been developed to identify materials with inverted singlet-triplet (INVEST) energy levels. This protocol surpasses existing quantum chemical methods in both accuracy and computational efficiency for predicting Δ<i>E</i>_ST, addressing challenges in high-throughput screening for INVEST materials. Based on this approach, novel heptazine derivatives have been proposed, which are anticipated to outperform currently known systems. Additionally, dynamic spin polarization (DSP) has been identified as a critical factor influencing INVEST phenomena. This insight provides a foundation for new design principles, enabling the discovery of materials with superior performance compared to existing alternatives.