Outstanding improvement in removing the delocalization error by global natural orbital functional

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Electronic Structure Theory

Background:

• Charge delocalization error is a persistent challenge in electronic structure calculations.
• Accurate description of static and dynamic electron correlation is crucial for reliable molecular modeling.
• Existing functionals struggle with systems exhibiting multi-configurational character.

Purpose of the Study:

• To evaluate the performance of the global natural orbital functional (GNOF) in mitigating charge delocalization errors.
• To assess GNOF's ability to balance static and dynamic electron correlations.
• To investigate GNOF's accuracy for systems with significant multi-configurational character.

Main Methods:

• Analysis of charge distribution in two-fragment super-systems.
• Assessment of ionization potential stability with increasing system size.
• Evaluation of potential energy curves for diatomic systems (neutral and charged).

Main Results:

• GNOF effectively eliminates or significantly reduces charge delocalization errors in various systems.
• GNOF demonstrates a favorable balance between static and dynamic electronic correlations.
• Accurate total energies and preserved spin states were obtained, even for challenging multi-configurational systems.

Conclusions:

• GNOF represents a significant improvement over previous functionals like PNOF7 in addressing charge delocalization.
• The functional shows promise for accurate electronic structure calculations of complex molecular systems.
• GNOF's ability to handle multi-configurational character makes it a valuable tool in computational chemistry.