Structure And Electron Properties Of The Al₁₂H_x And Al₁₃H_x(x=1-13) Clusters By The DFT Calculation

Atomic clusters had attracted lots of interests in the last three decades. The considerable interest in this field is brought about by two major expectations. First, atomic clusters form a bridge between atomic and molecular physics and condensed matter physics; secondly, materials synthesized by assembling the most stable clusters may be technologically important. Unfortunately, there is no experimental technique that can provide direct information on cluster geo- metry. The only method that enables determination of cluster geometries at pr- esent is, thus, based on theoretical calculations. In this thesis Density function- al theory with B3LYP method for the exchange-correlation potential has been used to calculate the global equilibrium geometries and electronic structure of neutral,clusters containing Al12Hx(x=1-12) and Al13Hx(x=1-13) . The total en- ergies of these clusters are then used to study the evolution of their binding energy ,relative stability, and ionization potential as an increase of hydrogen number. I also calculate the HOMO-LUMO Gap to determine the cluster's relative stability. In this thesis, I found several new equilibrium geometries, such as: Al12H2,Al12H8,Al13H,Al13H3,Al13H5,Al13H7,Al13H10,Al13H13. The binding energy evolves monotonically with size. The neutral clusters Al13H conform to the jellium model, which is demonstrated to be due to the electronic shell closure. The calculated results agree very well with available experimental data on ionization potentials...