Non-nuclear attractors in small charged lithium clusters, Li

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• The non-nuclear attractor (NNA) is a topological feature in electron charge density distributions.
• Understanding bonding and electronic structure in small clusters is crucial for materials design.

Purpose of the Study:

• To investigate the presence and characteristics of the NNA in small charged lithium clusters (Limq, m=2-5, q=±1).
• To compare the efficacy of the Quantum Theory of Atoms in Molecules (QTAIM) and the Ehrenfest force (F(r)) partitioning schemes in detecting NNAs.
• To explore the relationship between NNA size, lithium-ion separation, and charge density sparseness.

Main Methods:

• Utilized the Quantum Theory of Atoms in Molecules (QTAIM) and the Ehrenfest force (F(r)) partitioning schemes.
• Analyzed electron charge density (ρ(r)) and metallicity (ξ(rb)) for various lithium cluster configurations.
• Systematically varied lithium-lithium separations to assess NNA persistence.

Main Results:

• NNAs were consistently detected by QTAIM in all Limq clusters, but not by F(r).
• Anionic and cationic lithium dimers represent extreme cases of NNA impact, linked to charge density sparseness.
• NNA size positively correlates with increased Li-Li separations; NNA is a persistent feature.
• Metallicity analysis supports QTAIM's ability to detect significant metallic character, unlike F(r).

Conclusions:

• QTAIM is a reliable method for detecting NNAs in charged lithium clusters, while F(r) is not.
• The NNA's presence and size are influenced by inter-atomic distances and charge distribution.
• Findings provide insights into electronic structure and bonding in lithium clusters, relevant for nano-device design.