An improved descriptor of cluster stability: application to small carbon clusters

Area of Science:

• Physical Chemistry
• Materials Science
• Computational Chemistry

Background:

• Mass spectra of gas-phase clusters reveal stability trends based on peak heights.
• Existing stability descriptors, like total energy comparison, have limitations in explaining experimental mass spectra details.

Purpose of the Study:

• To develop a more accurate descriptor for carbon cluster cation (CN+) stability.
• To improve the correlation between theoretical stability analysis and experimental mass spectral data.

Main Methods:

• Analysis of published mass spectra for CN+ clusters (N ≤ 16).
• Density functional calculations to obtain cluster energies.
• Comparison of a novel atom-evaporation energy descriptor with traditional total energy methods.

Main Results:

• The traditional total energy descriptor showed unsatisfactory correlation with mass spectral peak variations.
• A new stability index based on atom-evaporation energies significantly improved the correlation with mass peak heights.
• The improved correlation is attributed to atom-evaporation energies directly relating to cluster abundance in beams.

Conclusions:

• Atom-evaporation energy is a superior descriptor for carbon cluster stability compared to total energy.
• The novel descriptor provides a better understanding of the processes governing cluster abundances in mass spectra.
• This work offers a refined approach for interpreting cluster beam mass spectrometry data.