Optimal Tuning of Range-Separated Hybrids for Solvated Molecules with Time-Dependent Density Functional Theory

The applicability range of density functional theory (DFT) can be improved with no additional parametrization by imposing some exact conditions. Enforcing equality between the orbital energy of the highest occupied Kohn-Sham orbital and ionization energy, determined from the total energy difference between neutral and ionized states (ΔKS), leads to the concept of optimally tuned range-separated hybrid functionals. Here, we present an alternative tuning scheme for range-separated hybrid functionals based on enforcing the equality between the ΔKS ionization energy and the ionization energy calculated by means of the time-dependent DFT using the concept of ionization as an excitation to the distant center (OT-IEDC scheme). The scheme can be naturally applied to solvated systems described either within the explicit solvation or dielectric continuum models. We test the performance of the scheme on a benchmark set of molecules. We further show that the scheme allows for reliably modeling liquid phase photoemission spectra.