Mutual orientation of two C60 molecules: an ab initio study.

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Fullerene C(60) is a key molecule in materials science, with its crystal structure and intermolecular interactions crucial for its properties.
• Understanding the bonding and orientation of C(60) molecules is essential for predicting and designing fullerene-based materials.
• Previous studies on C(60) interactions have relied on empirical potentials or limited ab initio calculations.

Purpose of the Study:

• To investigate the orientational dependence of the interaction between two C(60) molecules.
• To determine the preferred binding configurations and assess the accuracy of current models for C(60) bonding.
• To compare ab initio results with experimental data and previous theoretical findings.

Main Methods:

• Ab initio calculations using density functional theory (DFT) in the local density approximation (LDA).
• Computation of binding energies for various C(60)-C(60) orientations.
• Comparison of calculated binding energies with experimental heat of sublimation and previous theoretical studies.

Main Results:

• The calculated binding energy is significantly lower than that derived from experimental fullerite sublimation, questioning the nature of inter-C(60) bonding.
• The experimentally observed hexagon-hexagon bond to pentagonal face orientation is not the most stable configuration.
• Pentagon-facing-pentagon and hexagon-facing-hexagon-hexagon bond configurations are found to be slightly more favorable.

Conclusions:

• The nature of inter-C(60) bonding in fullerite may differ from current assumptions based on experimental sublimation energy.
• Accurate ab initio calculations are necessary to determine the true preferred orientations and energetics of C(60) interactions.
• Further investigation into C(60) stacking in clusters and crystals is warranted based on these findings.