Molecular crystals vs. superatomic lattice: a case study with superalkali-superhalogen compounds

Area of Science:

• Materials Science
• Computational Chemistry
• Solid-State Physics

Background:

• Atomically-precise cluster solids offer unique properties.
• Controlling assembly of these solids is key for new materials.

Purpose of the Study:

• To investigate the co-assembly of binary cluster solids using charge transfer.
• To explore the role of electrostatic attraction in forming molecular crystals and superatomic lattices.

Main Methods:

• First-principles calculations were employed.
• Analysis of binding energy, charge transfer, and cluster size.
• Studied superalkali (electron-donating) and superhalogen (electron-accepting) clusters.

Main Results:

• Binary cluster assemblies form either molecular crystals or superatomic lattices.
• Specific compounds like [N4Mg6Li]+[AlCl4]- form close-packed superatomic lattices via halogen bonding.
• Single atom substitution can significantly alter crystal structure and packing.

Conclusions:

• The structure of superatomic solids is tunable via single atom substitution.
• Charge transfer and electrostatic interactions are crucial driving forces for co-assembly.
• This work provides a pathway for designing novel cluster-based materials.