First-Principles Calculations of Structural Electronic Vibrational and Magnetic Properties of C60 and C48 N12: A Comparative Study

Published

February 1, 2003

Author(s)

Rui-Hua Xie, G C. Bryant, L Jensen, V H. Smith

Abstract

The structural, electronic, vibrational, and magnetic properties of the C₄₈N₁₂ azafullerene and C₆₀ are comparatively studied from the first-principles calculations. Full geometrical optimization and Mulliken charge analysis are performed. Electronic structure calculations of C₄₈N₁₂ show that the highest occupied molecular orbital (HOMO) is a doubly degenerate level of a_g symmetry and the lowest unoccupied molecular orbital (LUMO) is a nondegenerate level of a_u symmetry. The calculated binding energy per atom and HOMO-LUMO energy gap of C₄₈N₁₂ are about 1 eV smaller than those of C₆₀. Because of electron correlations, the HOMO-LUMO gap decreases about 5 eV and the binding energy per atom increases about 2 eV. The average second-order hyperpolarizability of C_48Nd12^ is about 55% larger than that of C₆₀. Our vibrational frequency analysis predicts that C₄₈N₁₂ has 58 infrared-active and 58 Raman-active vibrational modes. Two different methods for calculating nuclear magnetic shielding tensors of C₆₀ and C₄₈N₁₂ are compared, and we find that C₄₈N₁₂ exhibits eight ¹³C and two ¹⁵N NMR spectral signals. Our best-calculated results for C₆₀ are in excellent agreement with experiment. Our results suggest that C₄₈N₁₂ has potential applications as semiconductor components, nonlinear optical materials, and possible building blocks for molecular electronics and photonic devices.

Citation

Journal of Chemical Physics

Volume

118

Issue

No. 19

Pub Type

Journals

Keywords

ab initio, azafullerene, C₆₀, DFT, hyperpolarizability, infrared, NMR, polarizability

Citation

Xie, R. , Bryant, G. , Jensen, L. and Smith, V. (2003), First-Principles Calculations of Structural Electronic Vibrational and Magnetic Properties of C₆₀ and C₄₈ N₁₂: A Comparative Study, Journal of Chemical Physics (Accessed September 17, 2024)