부산대학교 도서관

Fullerene C60 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 C23 (one carbon pentagon ring among hexagon network), C22 (two), and C21 (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 C23. Second largest band at 17.4 micrometer appeared both in C22 and C21. Other major bands from 6 to 10 micrometer were reproduced well by a combination of C23, C22 and C21. Similarly, larger size graphene molecules of C53, C52 and C51 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 would be major component of astronomical carbon. Fullerene C60 would be one of them.