The structural, electronic, vibrational, and magnetic properties of the C 48 N 12 azafullerene and C 60 are comparatively studied from the first-principles calculations. Full geometrical optimization and Mulliken charge analysis are performed. Electronic structure calculations of C 48 N 12 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 C 48 N 12 are about 1 eV smaller than those of C 60 . 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 48 N 12 is about 55% larger than that of C 60 . Our vibrational frequency analysis predicts that C 48 N 12 has 58 infrared-active and 58 Raman-active vibrational modes. Two different methods for calculating nuclear magnetic shieldingtensors of C 60 and C 48 N 12 are compared, and we find that C 48 N 12 exhibits eight 13 C and two 15 N NMRspectral signals. Our best-calculated results for C 60 are in excellent agreement with experiment. Our results suggest that C 48 N 12 has potential applications as semiconductor components, nonlinear optical materials, and possible building blocks for molecular electronics and photonic devices
