Basis Set Convergence of Nuclear Magnetic Shielding Constants Calculated by Density Functional Methods

Area of Science:

• Computational Chemistry
• Quantum Chemistry

Background:

• Nuclear magnetic shielding constants are crucial for interpreting NMR spectra.
• Density functional theory (DFT) is widely used for electronic structure calculations.
• Basis set choice significantly impacts the accuracy of calculated properties.

Purpose of the Study:

• To evaluate existing polarization consistent basis sets for calculating nuclear magnetic shielding constants using DFT.
• To develop improved basis sets for accurate and efficient calculation of these constants.

Main Methods:

• Evaluation of polarization consistent basis sets (pcS-n) for nuclear magnetic shielding constants.
• Modification of basis sets by adding p-type functions with large exponents.
• Assessment of basis set convergence and performance in DFT calculations.

Main Results:

• Basis set convergence for nuclear magnetic shielding constants can be enhanced.
• Adding a single p-type function with a large exponent improves results.
• The modified pcS-n basis sets demonstrate superior performance.

Conclusions:

• The developed pcS-n basis sets are suitable for calculating nuclear magnetic shielding constants with DFT.
• These improved basis sets offer better accuracy at a comparable computational cost.
• The findings provide a more reliable computational tool for NMR spectroscopy analysis.