Void defect induced magnetism and structure change of carbon material-2,
  Graphene molecules
  Void-defect is a possible origin of ferromagnetic feature on pure carbon
materials. In our previous paper, void-defect on graphene-nanoribbon show
highly polarized spin configuration. In this paper, we studied cases for
graphene molecules by quantum theory, by astronomical observation and by
laboratory experiment. Model molecules for the density functional theory are
graphene molecules of C23 and C53 induced by a void-defect. They have carbon
pentagon ring within a hexagon network. Single void has three radical carbons,
holding six spins. Those spins make several spin-states, which affects to
molecular structure and molecular vibration, finally to infrared spectrum. The
stable spin state was triplet, not singlet. This suggests magnetic pure carbon
molecule. It was a surprise that those molecules show close infrared spectrum
with astronomically observed one, especially observed on carbon rich planetary
nebulae. We could assign major band at 18.9 micrometer, and sub-bands at 6.6,
7.0, 7.6, 8.1, 8.5, 9.0 and 17.4 micrometer. Also, calculated spectrum roughly
coincides with that of laboratory experiment by the laser-induced carbon
plasma, which is an analogy of cosmic carbon creation in interstellar space.
