Ab initio Calculations of Some Electronic and Vibrational Properties of Molecules Based on Multi-Layered Stacks of Cyclic C₆

Abstract

The vibrational and electronic properties of a class of novel carbon molecules constructed from stacked layers based on cyclic C₆ components have been studied using first principles density functional techniques. Data are presented for tubular stacked cyclic C₆ molecules (C₆)_n with 2 ≤ n ≤ 16. Infrared and Raman spectra have been calculated for all molecules. We find that a number of low energy infrared and Raman modes have energies that are strongly correlated with the overall length of the (C₆)_n structure, but the energy of the radial breathing mode is identical to that predicted for a single-walled carbon nanotube with a diameter of 0.295 nm. The HOMO-LUMO energy gap and the ionization energy approach 2.28 ± 0.02 eV and 6.8 ± 0.3 eV, respectively, in longer molecules. (C₆)_n molecules are found to have high stability and may be promising candidates for nanoelectronic applications.

Keywords:

• Carbon nanotubes
• ab initio calculations
• Raman spectrum
• IR spectrum

Acknowledgments

This work was supported by a grant from the NSERC and was made possible by the facilities of the Shared Hierarchical Academic Research Computing Network (SHARCNET: www.sharcnet.ca).