Estimating Phosphorescent Emission Energies in Ir^III Complexes Using Large-Scale Quantum Computing Simulations.

Area of Science:

• Quantum chemistry
• Computational materials science
• Photophysics

Background:

• Phosphorescent iridium complexes are crucial for organic light-emitting diodes (OLEDs).
• Accurate prediction of triplet-singlet (T1 → S0) transition energies is vital for designing efficient phosphorescent materials.
• Classical computational methods like Density Functional Theory (DFT) have limitations in predicting structure-property relationships.

Purpose of the Study:

• To evaluate the potential of quantum simulations, specifically the iterative qubit coupled cluster (iQCC) method, for calculating T1 → S0 transition energies.
• To compare the accuracy and predictive power of iQCC against established classical methods (DFT, ab initio) and empirical data.
• To establish a benchmark for quantum advantage in the field of organometallic complex design.

Main Methods:

• Calculation of T1 → S0 transition energies for nine phosphorescent iridium complexes using the iQCC method.
• Implementation of iQCC on a quantum simulator utilizing classical hardware due to the non-existence of sufficiently large quantum computers.
• Comparative analysis of iQCC results with DFT functionals, ab initio methods, and experimental data.

Main Results:

• The iQCC method achieves accuracy comparable to the best DFT functionals for T1 → S0 transition energies.
• iQCC demonstrates a superior correlation coefficient compared to DFT, indicating enhanced prediction of structure-property relationships.
• The study identifies a target for demonstrating quantum advantage in materials design.

Conclusions:

• The iQCC method shows significant potential for accurate prediction of electronic transitions in organometallic complexes.
• Quantum simulations, once deployable on fault-tolerant quantum hardware, can offer advantages over classical methods for materials discovery.
• The iQCC approach provides an industrially relevant target for future quantum computing applications in chemistry.