Study of the geometrical optimization and energy Gap of AlAs diamondoids

The electronic structure of zinc blend AlAs diamondoids was investigated using density functional theory at the local spin density approximation with double zeta functions that include polarization functions (LSDA/6-31G+(d,p)). Different sizes of diamondoids are investigated. The investigated properties include geometrical optimization, comparison between the bond length in the different structures, density of bonds, total energy, EHOMO, ELUMO and energy gap. The results showed that the energy gap of these structures was mostly reduced with increasing the number of Al and As atoms. This result is in good agreement with experimental results.-