Density functional theory study of CsC(n)- (n = 1-10) clusters

Area of Science:

• Computational Chemistry
• Materials Science
• Atomic and Molecular Physics

Background:

• Understanding the stability and structure of alkali metal-carbon clusters is crucial for developing new materials.
• Cesium carbon clusters (CsC(n)(-)) are of interest due to their unique electronic and structural properties.

Purpose of the Study:

• To investigate the ground-state structures and stability of cesium carbon clusters CsC(n)(-) for n = 1-10.
• To elucidate the factors contributing to the observed even-odd alternation in cluster stability.

Main Methods:

• Density functional theory (DFT) calculations using the B3LYP functional.
• Geometry optimization and vibrational frequency calculations were performed.
• Analysis of electronic stabilization, binding energy, electron affinity, and dissociation channels.

Main Results:

• Identified CsC(n)(-) clusters (n = 4-10) with cesium lightly embraced by the carbon chain as ground-state isomers.
• Observed that even-length carbon chains (n = 4-10) exhibit a polyacetylene-like structure.
• Found that CsC(n)(-) clusters with even n are more stable than those with odd n, consistent with mass spectrometric data.

Conclusions:

• The enhanced stability of even-numbered CsC(n)(-) clusters is attributed to electronic stabilization of the C(n)(2-) dianion by Cs(+).
• The even-odd alternation in stability is explained by variations in vibrational frequency, incremental binding energy, electron affinity, and dissociation pathways.
• The findings provide a theoretical basis for experimental observations of cesium carbon cluster stability.