IR-Raman of Silicon Carbide Nanocrystal Cluster and Vibrational Spectroscopy Properties at the PBE/6–31G

Abstract

The IR and Raman spectra are implemented to in gate the vibrational properties for silicon carbide (SiC) by using the density functional theory (DFT) at the PBE/6–31G level and include the polarization functions basis. The vibrational spectrum frequencies were studied also for the reduce masses, force constants, vibration intensities and depolarization spectra. In the last section, a comparative account changes the size related in certain frequencies of vibrational at SiC diamondoids with regards to the bulk in experimental. All results showed decrease the energy gap and density of states with increasing the size from diamantane to octamantane while the highest peak of bond length has register at 1.93 Å in octamantane. The tetrahedral angles of octamantane is 109° then that is much closer to the ideal value 109.2°. The high reduced mass mode (HRMM) and high force constant mode (HFCM) were larger than of the diamondoids in tetramantane were found 465.11 cm-1 and 864.40 cm-1 respectively.