Musa Heidari Nezhad Janjanpour - Department of Chemistry, Payame Noor University, P. O. Box: ۱۹۳۹۵-۴۶۹۷ Tehran, Iran
Mahshad Vakili - Young Researchers and Elite Club, Miyaneh Branch, Islamic Azad University, Miyaneh, Ir
Shahla Daneshmehr - Young Researchers and Elite Club, Mashhad Branch, Islamic Azad University, Mashhad, I
Khodadad Jalalierad - Department of Chemistry, Payame Noor University, P. O. Box: ۱۹۳۹۵-۴۶۹۷ Tehran, Iran
Fatemeh Alipour - Department of Chemistry, Payame Noor University, P. O. Box: ۱۹۳۹۵-۴۶۹۷ Tehran, Iran

In this work, the theoretical investigations on the buckyball systems including C۲۰, C۲۴, C۲۶, C۲۸, C۳۰ and C۱۹Si were done to study the structures and properties of different carbon nanoclusters. The geometries of all species were performed at the B۳LYP and PBE۱PBE levels using the ۶-۳۱+G (d) basis set. The HOMO–LUMO energy gap, ionization potential, electron affinity, chemical potential, electronegativity, global hardness and softness, electrophilicity and maximum amount of electronic charge of studied clusters were computed. The results showed that the computed electronic properties were considerable influenced by the size of different carbon nanoclusters. The Si atom doped instead of the carbon atom in C۲۰ was investigated

Fullerene, C۲۰-C۳۰, Carbon nanoclusters, HOMO–LUMO energy gap, DFT