AROFRAG─A Systematic Approach for Fragmentation of Aromatic Molecules.

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Chemistry

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are crucial in materials science.
• Accurate electronic energy calculations are vital for understanding molecular properties.
• Existing fragmentation methods can struggle with preserving aromaticity.

Purpose of the Study:

• To develop a novel, systematic fragmentation scheme for PAHs, fullerenes, and nanotubes.
• To preserve the fundamental unit of aromaticity during molecular decomposition.
• To enable accurate and computationally efficient electronic energy calculations.

Main Methods:

• Introducing the Aromatic Fragmentation (AROFRAG) approach, treating sextet rings as unbreakable units.
• Generating predefined elementary subsystems with weights to reconstruct the original molecule.
• Employing the molecule-in-molecule (MIM) technique for precise electronic energy descriptions.
• Applying AROFRAG to graphene, doped fullerenes, nanotubes, and fullerene molecules.

Main Results:

• The AROFRAG method successfully preserves aromaticity during fragmentation.
• Isomerization energies for graphene and doped fullerenes were accurately calculated.
• The combination of the third AROFRAG model and MIM achieved milli-hartree accuracy.
• Achieved accurate electronic energy reproduction at a significantly reduced computational cost.

Conclusions:

• AROFRAG offers a robust and efficient method for fragmenting complex aromatic systems.
• The AROFRAG-MIM combination provides a highly accurate and cost-effective approach for electronic energy calculations.
• This method advances the computational study of PAHs, fullerenes, and nanotubes.