Performance of a nonempirical density functional on molecules and hydrogen-bonded complexes

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Materials Science

Background:

• The development of accurate density functionals is crucial for computational chemistry.
• Generalized gradient approximation (GGA) functionals are widely used but have limitations.
• The Tao-Mo functional is a recent meta-generalized gradient approximation (meta-GGA) based on a model exchange-correlation hole.

Purpose of the Study:

• To evaluate the performance of the newly developed Tao-Mo functional.
• To compare the Tao-Mo functional against established functionals like LSDA, PBE, and TPSC.
• To assess accuracy across a wide range of chemical and physical properties.

Main Methods:

• The Tao-Mo functional was applied to standard computational chemistry test sets.
• Calculations utilized the 6-311++G(3df,3pd) basis set.
• Performance was evaluated for enthalpies of formation, atomization energies, barrier heights, electron affinities, proton affinities, bond lengths, vibrational frequencies, hydrogen-bonded complexes, and atomic excitation energies.

Main Results:

• The Tao-Mo functional demonstrated high accuracy for most tested properties.
• It outperformed LSDA, PBE, and TPSC functionals in several key areas.
• Exceptional accuracy was observed for proton affinities, harmonic vibrational frequencies, hydrogen-bond energies/lengths, and atomic excitation energies.

Conclusions:

• The Tao-Mo functional represents a significant advancement in density functional theory.
• It offers a reliable and accurate option for predicting various molecular and atomic properties.
• Its superior performance in specific areas makes it a valuable tool for chemical research.