A face-sharing bi-icosahedral model for Al₂₃⁻

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Chemistry

Background:

• Magic clusters exhibit enhanced stability due to specific electronic shell closures.
• Aluminum clusters are of interest for their unique electronic and structural properties.

Purpose of the Study:

• To determine the likely atomic structure of the magic aluminum cluster Al23(-).
• To elucidate the electronic structure and bonding in Al23(-) and related clusters.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of superatomic orbital overlap was performed.

Main Results:

• A face-sharing bi-icosahedral motif is proposed as the candidate structure for Al23(-).
• The Al23(-) structure is described as a quasi-molecule composed of two Al13 (D3d) superatoms.
• An open electronic configuration arises from the overlap of 1F and 2P superatomic orbitals.
• A face-sharing tri-icosahedral motif is predicted for Al33(-).

Conclusions:

• The proposed structure provides a plausible explanation for the magic nature of Al23(-).
• The superatom concept is applicable to understanding the electronic structure of these aluminum clusters.
• DFT calculations are effective in predicting cluster structures and properties.