Excited state properties of point defects in semiconductors and insulators using TD-DFT with dielectric-dependent range-separated hybrid functionals

Recently, we introduced the screened-exchange range-separated hybrid (SE-RSH) functional that accounts for spatially varying dielectric screening in complex materials [1-2]. We showed that SE-RSH yields results in good agreement with experiments for the band gaps and dielectric constants of a broad range of semiconductors and insulators, including heterogeneous systems with a large dielectric mismatch. Here, we extend SE-RSH to time-dependent density-functional theory (TDDFT) and assess its performance in calculating excited-state properties of defects in diamond and magnesium oxide, explicitly accounting for excited-state structural relaxations via an efficient implementation of analytical forces at the level of TDDFT for periodic systems [3]. Comparison with experiment indicates that TDDFT with SE-RSH can be used for robust predictions of the excited states properties of point defects in semiconductors and insulators.

[1] J. Zhan, M. Govoni, and G. Galli, J. Chem. Theory Comput. 19 (17), 5851-5862 (2023).

[2] J. Zhan, M. Govoni, and G. Galli, Phys. Rev. Mater. 9, 053808 (2025).

[3] Y. Jin et al., J. Chem. Theory Comput. 19, 8689 (2023).