Range-separated hybrid and double-hybrid density functionals: A quest for the determination of the range-separation...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Range-separated hybrid and double-hybrid density functionals are crucial in computational chemistry.
• Determining the range-separation parameter is key to their accuracy.
• Existing methods like optimal tuning (OT) can be computationally intensive.

Purpose of the Study:

• To introduce and validate a new, simple method for determining the range-separation parameter.
• To assess the performance of this new method against the established optimal tuning (OT) approach.
• To confirm the reliability and efficiency of the proposed method for density functional theory (DFT) calculations.

Main Methods:

• Derived a novel route for range-separation parameter determination.
• Imposed a constraint on exchange-correlation energy to recover the hydrogen atom's total energy.
• Statistically compared the new method's parameters with those from the optimal tuning (OT) approach.

Main Results:

• The new method closely agrees with the optimal tuning (OT) approach.
• The method demonstrates comparable performance in computing properties sensitive to self-interaction errors, such as ionization potentials.
• Validated the reliability and accuracy of the new range-separation parameter determination technique.

Conclusions:

• The proposed method is a reliable and efficient alternative to the optimal tuning (OT) procedure.
• It maintains the accuracy and efficiency of standard Kohn-Sham density-functional theory.
• This work simplifies parameter determination in advanced density functional approximations.