Theoretical Study as Nano Structure for Fluorine Phenanthrene Molecules(crystal ) Group: by B3LYP-DFT

Abstract

In this work, five molecules are optimized at B₃LYP/6-31G^** density functional theory (DFT). Phenanthrene molecule was a reference. The electronic properties nano structure of fluorine Phenanthrene molecules group were investigated depending; include the bond molecules , nano structure for crystal,  total energy, electronic states, electron affinity, chemical hardness, softness and electrophlicity index.Adding the fluorine atoms to the original ring (Phenanthrene molecule)  leads to decrease the energy gap and the hardness of the molecule. The results show that these molecules are more effective with small energy gap compared with Phenanthrene molecule. This may indicates that these structures represent new electronic materials. The vibrational frequencies of fluorine Phenanthrene molecules group supplies new data.

Key words: DFT, energy gap, ionization potential, hardness and IR- spectrum.