The vibrational frequencies and corresponding normal mode assignments of cyanogen azide are examined theoretically using the Gaussian03 set of quantum chemistry codes. All normal modes were successfully assigned to one of seven types of motion predicted by a group theoretical analysis (N
N stretch, N
N stretch, N–C stretch, C
N stretch, N
N
N bend, N
N–C bend, and N–C
N bend). Theoretical infrared and Raman intensities are reported. The molecular orbitals and bonding of cyanogen azide are examined.