Importance of the correlation contribution for local hybrid functionals: range separation and self-interaction...

Area of Science:

• Quantum Chemistry
• Computational Materials Science
• Density Functional Theory

Background:

• Local hybrid functionals, an extension of hybrid functionals, incorporate position-dependent exact-exchange admixture.
• Previous studies utilized local spin density approximation (LSDA) correlation functionals with local hybrids, yielding favorable results for atomization energies.
• The choice of correlation functional significantly impacts the parameterization and performance of local hybrid exchange functionals.

Purpose of the Study:

• To investigate the influence of correlation functionals on local hybrid functional performance.
• To propose a novel ansatz for the correlation part of local hybrids.
• To improve the accuracy of local hybrids for properties sensitive to self-interaction errors.

Main Methods:

• Developing a novel correlation functional based on range-separation of LSDA correlation into short-range (SR) and long-range (LR) parts.
• Implementing partial or full elimination of one-electron self-correlation from the SR part.
• Evaluating the performance of the modified functionals for thermochemistry, reaction barriers, and other properties.

Main Results:

• The novel correlation functional approach allows for a larger exact exchange admixture in local hybrids.
• This leads to improved accuracy for reaction barriers and properties affected by self-interaction errors.
• The range-separation method provides new insights into the decomposition of correlation energy.

Conclusions:

• The proposed correlation functional ansatz enhances the performance of local hybrid functionals.
• Addressing self-interaction errors through modified correlation is crucial for accurate predictions.
• This work offers a refined understanding of correlation energy components in density functional theory.