Structural distortions of fullerene C60n (n = 0 to −6) by first principle density functional theory

Abstract

The anions of C60 fullerene have geometrically multiple distortions. These geometric changes of C60 were directly related to the orbital changes called structural distortion effects. In this study, neutral C60 fullerene and its −1 to −6 anions were optimized by using DFT method. The geometric changes and the electronic properties were also investigated. Unrestricted calculations were applied to investigate the energy gap changes and density of states (DOS) spectrums as well. The electron localization function (ELF) along with the natural bond orbital (NBO) calculations were presented the considerable images from the changes of electron properties of C60 fullerene. The results show that in −5 and −6 anions lost π bonds and also can see creation of non-bonding lone pair in −6 anion. The calculations on the vibrational levels, structural changes such as changes in diameters and dipole moments of C60n (n = 0 to −6) were investigated as well. The most stable spin forms of the optimized C60 structures were chosen to observe structural distortions by using the DFT computational method. For some of the anions the wide changes of forms, energies of the valance orbitals and the energy states were investigated for the low and high spins. Also, the spin channel phenomenon was studied by using the results of DFT-B3LYP/6-31G∗ calculations. The NBO analysis was performed due to its beneficial information in the changes of fullerene electronic system properties for all the anion states in the selected computational level method. The changes of the calculated IR spectra patterns have discussed due to the charge changes of C60n (n = 0 to −6) and on the basis of the structural distortions role (John-Teller effect). A linear equation was obtained by using graph theory (GT) between the energy of HOMO and/or LUMO orbitals and load amount of anions. The DOS spectrums and HOMO and LUMO orbitals in the different discussed spin states show that all fullerene anions have different spin behavior and magnetic specifications, in which anions −2 and −3 anions of C60 act as the spin channels.