C_(60),C_(180),C_(60)@C_(180)富勒烯分子的压缩力学特性与电子结构

Mechanical characters and electronic structures of compressed C_(60), C)_(180) and C_(60)@C_(180) fullerene molecules

采用分子动力学方法模拟了C60、C180、C60@C180富勒烯分子的压缩过程,用PM3半经验量子力学方法计算了压缩C60、C180、C60@C180分子的电子结构,讨论了C60、C180、C60@C180分子压缩力学特性的差异,以及电子结构在压缩过程中的变化．结果表明,由于分子几何构形上的差异,C60分子的承载与吸收能量能力显著高于C180和C60@C180分子,而 C60@C180分子略高于C180分子;C60分子具有最高的化学稳定性,而C60@C180分子的稳定性最低;C60和C60@C180 分子的压缩变形越大,越容易失去电子,稳定性越低;C180分子在加载点处发生压缩“塌陷”时,化学活性明显增加．

Molecular dynamics simulations were performed for compressed C6o, C18o and C60@C180 fullerene molecules, and PM3 semi-empirical quantum mechanics calculations were carried out to obtain the electronic structures of the compressed fullerenes. According to the obtained results, the differences of mechanical characters between these compressed fullerenes, as well as the variations of their molecular obital energy levels during the compressions, were discussed. The results show that the load-support and energy-absord capability of C60 molecule head and shoulder above those of C180 and C60@C180molecules, and C60@C180 is only lightly superior to C180. C60 molecule has the best chemical stability, and the stability of C60@C180 molecule is worst, with increasing of compression strain, both C80 and C60@C180 molecules become more chemically active, and when compressed C180 molecule caves in at the load side （or sides）, its chemical stability will reduce abruptly.