Structures of Pb(n) (n = 21-30) clusters from first-principles calculations

Area of Science:

• Computational materials science
• Atomic and molecular physics
• Quantum chemistry

Background:

• Understanding the structural and electronic properties of atomic clusters is crucial for developing new materials.
• Lead clusters, in particular, present unique electronic behaviors due to relativistic effects.

Purpose of the Study:

• To investigate the stable structures of neutral lead clusters (Pb(n), n = 21-30).
• To determine the energetic stability and electronic properties of these lead clusters.
• To identify particularly stable lead cluster configurations.

Main Methods:

• Utilized a genetic algorithm (GA) combined with tight-binding (TB) calculations for structural searching.
• Employed density functional theory (DFT) with the Perdew-Burke-Ernzerhof (PBE) functional for accurate electronic structure calculations.
• Analyzed binding energies, cluster stabilities, and highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps.

Main Results:

• Identified a preference for endohedral cage structures in Pb(n) clusters for n = 22-30.
• Observed that Pb(22-26) clusters favor two endohedral atoms, while Pb(27-30) favor three.
• Highlighted Pb(24) and Pb(28) as exceptionally stable clusters compared to their neighbors.
• Calculated binding energies, stabilities, and HOMO-LUMO gaps for the studied clusters.

Conclusions:

• Neutral lead clusters exhibit a tendency towards endohedral cage structures with increasing size.
• Specific lead cluster sizes, namely Pb(24) and Pb(28), demonstrate significant enhanced stability.
• The findings provide valuable data for understanding the fundamental properties of lead atomic clusters.