Electronic Structure Calculations of Carbon Nanohorns for Their Chemical State Analysis Using Soft X-Ray Spectroscopy

The electronic structure of carbon nanohorns (CNHs) was calculated by the discrete variational -X alpha molecular orbital method to analyze the electronic structure and/or chemical state using soft X-ray spectroscopy. Five isomers of CNH,C115H25, C158H26, C135H21, C102H16, and C118H16, were successfully modeled. Slight differences in the electronic structure between the hexagonal and pentagonal rings of the CNH models can be understood from the orbital population, net charge, and bond overlap population. The calculated density of states in the C2p orbitals can be used for spectral analysis of soft X-ray emission and absorption in the CK region of CNH. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2728-2733, 2009