Accelerated long-range corrected exchange functional using a two-gaussian operator combined with one-parameter...

Area of Science:

• Computational chemistry
• Quantum chemistry
• Theoretical chemistry

Background:

• Long-range corrected (LC) hybrid schemes in density functional theory (DFT) are crucial for accurate electronic structure calculations.
• Existing LC-DFT methods can be computationally intensive.
• The two-Gaussian attenuating operator offers a potential for computational efficiency.

Purpose of the Study:

• To develop and evaluate an efficient LC hybrid scheme using a two-Gaussian attenuating operator.
• To investigate the performance of LC-BOP(2Gau) with varying range-separation parameters for thermochemical and frontier orbital energies.
• To optimize the Gaussian multipole screening scheme for LC-DFT(2Gau).

Main Methods:

• Implementation of a modified two-Gaussian attenuating operator for the long-range Hartree-Fock exchange integral.
• Combination of the LC hybrid scheme with one-parameter progressive correlation and Becke88 exchange functionals (LC-BOP(2Gau)).
• Systematic variation of the range-separation parameter (μ) in LC-BOP(2Gau).
• Revision of scaling factors in the Gaussian multipole screening scheme for LC-DFT(2Gau) based on orbital angular momentum.

Main Results:

• LC-BOP(2Gau) with various μ values accurately reproduces thermochemical and frontier orbital energies.
• The computational efficiency of the LC-DFT(2Gau) scheme is significantly improved.
• Revised scaling factors for the Gaussian multipole screening scheme reduced energy deviations compared to the no-screening approach.

Conclusions:

• The LC-BOP(2Gau) method provides an efficient and accurate approach for electronic structure calculations.
• The two-Gaussian attenuating operator is a viable alternative for improving the computational performance of LC-DFT.
• Optimized screening schemes further enhance the accuracy of LC-DFT(2Gau).