This arrangement has other meaning. Within the TB approximation, effect of charge transfer is not described. On the other hand, B (N) atoms act as acceptors Everolimus solubility dmso (donors) in graphene. Since B and N atoms occupy the same sublattice sites, the effect of charge transfer is canceled when the atoms are arranged as B-C-N-C along zigzag lines. Therefore, TB model is applicable for the zigzag BC2N nanoribbons when the atoms are arranged as B-C-N-C along zigzag lines. Conclusions The electronic properties of BC2N nanoribbons with zigzag edges have been studied theoretically using the tight binding model and the first-principles calculations. When atoms are arranged

as B-C-N-C along the zigzag lines, the zigzag BC2N nanoribbons have the flat bands. Then, the tight binding model can become applicable for these systems. In this arrangement, the charge transfer is averaged effectively since B and N atoms are substituted in same sublattice sites, and such effect plays an important role for the formation of the edge states.

For the tight binding model, the ratio of the site energies of B atom to Selleckchem Enzalutamide the hopping integral is larger than unity. We tried to describe the band structure of BC2N nanoribbons where the atoms are not arranged as B-C-N-C along the zigzag lines using the tight binding model by introducing the extra site energies at the outermost atoms, but such method does not work for some BC2N nanoribbons. Therefore, study on the electronic properties of BC2N nanoribbons

diglyceride should be done within the first-principles calculations. Acknowledgements The authors acknowledge H. Imamura, Y. Shimoi, H. Arai, H. Tsukahara, K. Wakabayashi, and S. Dutta for valuable discussions. This research was supported by the International Joint Work Program of Daeduck Innopolis under the Ministry of Knowledge Economy (MKE) of the Korean Government. References 1. Fujita M, Wakabayashi K, Nakada K, Kusakabe K: Peculiar Selleck Anlotinib localized state at zigzag graphite edge. J Phys Soc Jpn 1996, 65:1920.CrossRef 2. Nakada K, Fujita M, Dresselhaus G, Dresselhaus MS: Edge state in graphene ribbons: nanometer size effect and edge shape dependence. Phys Rev B 1996, 54:17954.CrossRef 3. Weng-Sieh Z, Cherry K, Chopra NG, Blase X, Miyamoto Y, Rubio A, Cohen ML, Zettl A, Gronsky R: Synthesis of BxCyNz nanotubules. Phys Rev B 1995, 51:11229.CrossRef 4. Redlich P, Leoffler J, Ajayan PM, Bill J, Aldinger F, Rühle M: B-C-N nanotubes and boron doping of carbon nanotubes. Chem Phys Lett 1996, 260:2465.CrossRef 5. Sen R, Satishkumar BC, Govindaraj A, Harikumar KR, Raina G, Zhang JP, Cheetham AK, Rao CNR: B-C-N, C-N and B-N nanotubes produced by the pyrolysis of precursor molecules over Co catalysts. Chem Phys Lett 1998, 287:671.CrossRef 6.