A Theoretical Investigation of the Possible Detection of C24 in Space
  Astronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have
recently been suggested as being due to the planar graphene form of C24 carbon
cluster. Here we report density functional theory and coupled cluster
calculations on wavefunctions stability, relative energies, and infrared
spectra of four different types of C24 isomers, including the graphene and
fullerene forms. The types of vibrational motions under these bands are also
discussed. Among the four isomers, we find that the astronomical data are best
approximated by the graphene form of C24.
