Quantitative Prediction of Optical Absorption in Molecular Solids from an Optimally Tuned Screened Range-Separated...

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Predicting electronic properties of molecular solids is crucial for materials design.
• Traditional methods often face computational limitations for complex systems.
• Accurate prediction of fundamental gaps and optical spectra remains a challenge.

Purpose of the Study:

• To develop and validate a nonempirical, quantitative approach for predicting molecular solid properties.
• To utilize time-dependent density functional theory (TDDFT) with a novel functional for solid-state calculations.
• To benchmark the accuracy against established many-body perturbation theory methods.

Main Methods:

• Employed the optimally tuned screened range-separated hybrid (OT-SRSH) functional.
• Incorporated long-range dielectric screening for solid-state effects.
• Performed self-consistent periodic-boundary calculations for crystalline solids.
• Benchmarked against the X23 molecular solids set and GW-BSE calculations.

Main Results:

• Achieved quantitative and nonempirical predictions of fundamental gaps and optical spectra.
• Demonstrated the robustness of the OT-SRSH approach for molecular solids.
• Found that dielectric screening impacts fundamental gaps more than optical spectra.

Conclusions:

• The OT-SRSH functional approach provides accurate predictions for molecular solids.
• This TDDFT-based method is a viable and robust alternative to computationally intensive techniques.
• Enables studies of molecular solids previously beyond computational reach.