Hartree-Fock exchange fitting basis sets for H to Rn.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Hartree-Fock (HF) methods are fundamental in computational chemistry.
• Accurate electronic structure calculations require significant computational resources.
• Approximation methods are needed to improve efficiency.

Purpose of the Study:

• To present auxiliary basis sets for fitting exchange and Coulomb potentials in HF calculations (RI-JK-HF).
• To assess the accuracy and efficiency of these new auxiliary basis sets.
• To enable faster and more accurate quantum chemical computations.

Main Methods:

• Development of auxiliary basis sets for RI-JK-HF calculations.
• Testing on a diverse set of small molecules covering elements H to Rn.
• Evaluation of energy and wave function accuracy for triple and quadruple zeta valence orbital basis sets.

Main Results:

• RI-JK approximation introduces minimal errors (<1 meV/atom) in total energies for triple and quadruple zeta basis sets.
• Accuracy of RI-JK-approximated HF wave functions is sufficient for post-HF methods like MP2.
• Significant computational savings achieved, especially for larger basis sets and systems.

Conclusions:

• The developed RI-JK-HF auxiliary basis sets offer a computationally efficient yet accurate approach for electronic structure calculations.
• These methods are suitable for post-HF treatments, broadening their applicability.
• The approach provides substantial computational savings, accelerating research in quantum chemistry.