Mechanical properties and electronic structures of compressed C60, C180 and C60@C180 fullerene molecules

Molecular dynamics simulations were performed for compressed C60, C180 and C60@C180 fullerene molecules, and the semi-empirical PM3 calculations were carried out to obtain the electronic structure of the compressed fullerenes. According to the obtained results, the differences of mechanical properties between these compressed fullerenes, as well as the changes of their FMO (Frontier molecular orbital) energy-levels during compression, were discussed. It is shown that (1) the C60 molecule has much higher load-support and energyabsorbing capability than the C180 and C60@C180 molecules, and the C60@C180 is only slightly superior to the C180, (2) of the three molecules, the C60 molecule has the best chemical-stability, and the C60@C180 molecule has the worst one, (3) with the increase of compressive strain, both the C60 and C60@C180 molecules become more chemically active, and (4) when the compressed C180 molecule caves in at the loading position(s), its chemical-stability decreases abruptly