Magnetism and Astronomical Infrared Spectrum of Fullerene C60 and Void Induced Graphene Molecules

Abstract

Fullerene C 60 shows astronomical four infrared bands (IR) of carbon rich planetary nebulae. However, there remain many unidentified bands. Our previous paper revealed that single void-defect induced graphene molecule reproduce many astronomical bands. In this paper, we investigated a series of multiple-void induced graphene molecules. We tried spin dependent DFT calculation. Model molecules are C 23 (one carbon pentagon ring among hexagon network), C 22 (two), and C 21 (three). Those were all magnetic molecules with spin state of Sz =2/2, 2/2 and 4/2 respectively. Calculated IR was compared with astronomical observation. The largest astronomical band at 18.9 micrometer was found in C 23 . Second largest band at 17.4 micrometer appeared both in C 22 and C 21 . Other major bands from 6 to 10 micrometer were reproduced well by a combination of C 23 , C 22 and C 21 . Similarly, larger size graphene molecules of C 53 , C 52 and C 51 were also magnetic and reproduced astronomical bands as well. Weighting sum IR of those molecules could successfully trace astronomical 12 bands from 6 to 20 micrometer. A series of multiple void induced graphene