Exploring an Adequate DFT Functional to Accurately Describe the Singlet Excited State Properties in HLCT Materials: A Benchmark Study

The popularly used global, meta-GGA, and range-separated hybrid DFT functionals are examined to compare the predictive qualities of singlet excited state (S1) properties in HLCT materials. Among these hybrid DFT functionals, it is clarified that both M06 and LC-omega*HPBE functionals show quantitatively and qualitatively excellent predictions of absorption energies, compared to experiments. However, a discrepant behavior in predicting the emission energy is found that LC-omega*HPBE functional obviously predicts more accurate emission energy than M06 functional. Also, the calculated tau s values by means of M06 and LC-omega*HPBE functionals show that LC-omega*HPBE functional gives quantitatively and qualitatively superior prediction. Consequently, it is suggested that LC-omega*HPBE functional should be used to conduct the essential photo-physical properties of HLCT materials in S-1 state.