Performance of Several Density Functional Theory Methods on Describing Hydrogen-Bond Interactions

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Hydrogen bonding (HB) is crucial in chemistry and biology.
• Accurate computational methods are needed to describe HB interactions.
• Density functional theory (DFT) is widely used for such calculations.

Purpose of the Study:

• To evaluate the performance of eleven density functionals for describing hydrogen bond interactions.
• To assess their accuracy in calculating absolute and relative hydrogen bonding energies.
• To determine the best functionals for predicting conformer stabilities.

Main Methods:

• Investigated eleven density functionals: LDA, PBE, mPWPW91, TPSS, B3LYP, X3LYP, PBE0, O3LYP, B97-1, MPW1K, and TPSSh.
• Calculated intermolecular hydrogen bonding energies.
• Predicted relative energies of intermolecular H-bonded complexes and intramolecular hydrogen bondings.

Main Results:

• PBE and PBE0 accurately estimated HB strengths but sometimes failed in predicting relative energies.
• TPSS and TPSSh offered limited improvement over PBE and PBE0.
• B3LYP underestimated HB strengths but performed well for relative energies.
• X3LYP and B97-1 provided accurate values for both absolute and relative HB energies.

Conclusions:

• X3LYP and B97-1 are recommended for accurate description of hydrogen bond interactions.
• These functionals show good performance for both absolute HB strengths and relative HB energies.
• The choice of functional significantly impacts the prediction of conformer stabilities.