Quantum Mechanical Study of Lithium Fluoride Clusters*

The materials of interest for this research are Li_n and F_n clusters (n = 2 thru 15), and the hybrid clusters formed from these mono-atomic clusters. The study of clusters can reveal the effects of substrate geometry on the behavior of adsorbates. Metal clusters and non-metal clusters are especially suited for the study of quantum size effects and for formation of metallic states, and are ideal candidates for catalytic processes. Hybrid ab initio methods of quantum chemistry (particularly the DFT-B3LYP model) will be used to derive optimal geometries for the clusters of interest. We compare calculated binding energies, bond-lengths, ionization potentials, electron affinities and HOMO-LUMO gaps for the clusters. Effects of crystal symmetries corresponding to the bulk structures will be investigated. Of particular interest is the class of lithium fluoride clusters of the type Li_nF, including Li₂F, Li₃F and Li₄F. Atomic and molecular clusters, generated by supersonic expansions, are a favorite medium for study of reactions and spectra. We will also study the rotational spectra of lithium clusters, fluorine clusters, and hybrid clusters.