Improved DFT Potential Energy Surfaces via Improved Densities.

Area of Science:

• Computational chemistry
• Quantum mechanics
• Density Functional Theory (DFT)

Background:

• Semilocal DFT calculations often fail for certain molecular properties.
• Accurate potential energy surfaces are crucial for understanding chemical reactions.
• Existing DFT methods struggle with severely stretched chemical bonds.

Purpose of the Study:

• To introduce and validate a novel density-corrected DFT (DC-DFT) method.
• To improve the accuracy of potential energy surfaces for heteronuclear molecules.
• To extend the applicability of DFT to challenging chemical systems.

Main Methods:

• Employing Hartree-Fock density within a DFT framework.
• Applying density correction to semilocal DFT calculations.
• Evaluating accuracy for neutral and charged molecules, including CH(+).

Main Results:

• DC-DFT significantly enhances accuracy for potential energy surfaces with stretched bonds.
• The method demonstrates success for both neutral and charged molecular systems.
• DC-DFT performance surpasses sophisticated methods like CCSD in specific cases (e.g., CH(+)).

Conclusions:

• Density-corrected DFT offers a robust improvement over standard semilocal DFT.
• The novel procedure extends the range of accurate electronic structure calculations.
• A simple criterion is provided to predict when DC-DFT outperforms self-consistent DFT.