Range-Separated Double-Hybrid Functional from Nonempirical Constraints.

Area of Science:

• Quantum Chemistry
• Computational Materials Science

Background:

• Development of accurate and efficient electronic structure methods is crucial in computational chemistry.
• Nonempirical double hybrid functionals offer a promising avenue, but often struggle with self-interaction error.

Purpose of the Study:

• To present a new, nonempirical double hybrid functional, RSX-QIDH.
• To evaluate its performance in reducing self-interaction error and predicting various chemical properties.

Main Methods:

• Development of a novel exchange-correlation functional (RSX-QIDH) using a range-separated exchange model and nonlocal perturbative correlation.
• Setting the range-separation parameter to reproduce the hydrogen atom's total energy.
• Benchmarking against established functionals using standard datasets.

Main Results:

• RSX-QIDH demonstrates significantly reduced self-interaction error.
• Accurate prediction of dissociation profiles for charged rare-gas dimers.
• Highly accurate ionization potentials derived directly from Kohn-Sham orbital energies.
• Competitive performance compared to empirical double hybrids like ωB97X-2.

Conclusions:

• RSX-QIDH offers a robust, nonempirical approach to electronic structure calculations.
• The nonlocal perturbative correlation is vital for achieving high accuracy.
• This functional is a promising tool for various quantum chemistry applications.