Predicting the Photoelectron Spectra of Quasi Octahedral Al₆Mo^- Cluster.

Area of Science:

• Computational chemistry
• Materials science
• Spectroscopy

Background:

• Experimental photoelectron spectra of mixed-metal clusters are complex.
• Distinguishing effects of size, composition, symmetry, and fluxionality is challenging.
• Previous studies explained Al13- and Al12Ni- spectra, and AlnMo- (n=3-5,7) spectra.

Purpose of the Study:

• To predict the photoelectron spectrum of the Al6Mo- cluster using a novel computational methodology.
• To investigate the structural and electronic properties of Al6Mo- and its isomers.
• To bridge the understanding between less symmetric Al5Mo- and Al7Mo- clusters.

Main Methods:

• Development of a computational methodology to separate spectral effects.
• Application of the methodology to analyze mixed-metal cluster photoelectron spectra.
• Prediction of the Al6Mo- spectrum, considering its high symmetry and potential fluxionality.

Main Results:

• The methodology successfully explains spectral differences in related clusters.
• Al7Mo- exhibits spectral broadening due to fluxionality (>=6 structures).
• Al6Mo- is predicted to have well-defined peaks with some broadening due to two low-lying isomers (D3d and D3h symmetry, 0.052 eV apart).

Conclusions:

• The computational methodology is effective for predicting and explaining cluster spectra.
• Fluxionality significantly impacts the spectral features of mixed-metal clusters.
• Al6Mo- presents a unique high-symmetry system with potential for tunable material properties.