Magic Numbers in Octahedral Ligated Metal-Chalcogenide Superatoms

Area of Science:

• * Cluster Chemistry
• * Materials Science
• * Quantum Chemistry

Background:

• * The superatomic state provides a unifying framework for classifying atomic clusters.
• * Metallic clusters often achieve this state through the confined nearly free electron gas model.
• * This model explains quantum state groupings based on quantum numbers.

Purpose of the Study:

• * To investigate the superatomic state in ligated octahedral metal-chalcogenide clusters (TM6E8L6).
• * To determine if high symmetry in these clusters can also lead to electronic state bunching.
• * To identify magic electron counts and associated electronic properties in these specific clusters.

Main Methods:

• * Computational analysis of electronic structure for octahedral TM6E8L6 clusters.
• * Examination of valence electron counts and their correlation with electronic shell filling.
• * Analysis of highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps, ionization energies, and electron affinities.

Main Results:

• * Identified magic electron counts of 96, 100, and 114 for octahedral TM6E8L6 clusters.
• * Observed that these magic counts correspond to large HOMO-LUMO gaps, high ionization energies, and low electron affinities, characteristic of the superatomic state.
• * Discovered periodic patterns in clusters with non-magic electron counts, mirroring trends in the periodic table of elements.

Conclusions:

• * The superatomic state is achievable in octahedral metal-chalcogenide clusters, even when the nearly free electron gas model is not applicable.
• * High symmetry plays a crucial role in creating the electronic shell structure.
• * These findings suggest a potential for a periodic classification of atomic clusters analogous to that of elements.