Basis Set Extrapolations for Density Functional Theory.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Basis set extrapolation is a standard method in wavefunction theory to improve computational accuracy.
• Density functional theory (DFT) calculations can be computationally expensive, especially with large basis sets.

Purpose of the Study:

• To develop and validate basis set extrapolation techniques for DFT.
• To enable more accurate and cost-effective DFT calculations using smaller basis sets.

Main Methods:

• Analogous techniques for basis set extrapolation in DFT were developed, focusing on [2,3]-ζ calculations.
• Included double hybrid and dispersion-corrected functionals, using finite element calculations for basis set limit data.
• Validated methods using the GMTKN55 and NCDT datasets, informed by Hartree-Fock extrapolation reviews.

Main Results:

• Extrapolation of [2,3]-ζ calculations in def2-Xzvpd and cc-pvXz-pp basis sets matched or outperformed 4-ζ calculations.
• Achieved comparable or better accuracy at a significantly reduced computational cost.
• The proposed recipes provide a practical and efficient approach to basis set extrapolation in DFT.

Conclusions:

• The developed basis set extrapolation techniques offer a cost-effective way to achieve high accuracy in DFT.
• These methods can significantly enhance the efficiency of computational chemistry workflows.
• Implementation in Psi4 allows for automated and user-friendly application of these techniques.