Properties of C60 and related compounds

本文采用Huckel近似下的一维紧束缚晶体轨道方法，研究了石墨螺旋管模型Bucky管的电子性质。根据螺距的不同，发现存在两种类型的grahelix，一种是能量稳定的，具有螺旋结构，另一种是不稳定的，具有金属性质，并阐明了这种金属管等价于含有多个孤立的顺式聚乙炔骨架的管，这些骨架大多以螺旋方式排列在管表面。这种螺旋状的聚乙炔骨架保证了到费米能级附近的电子的金属传导路径（螺旋子）。控制这些螺旋粒子的流动，可以为电子器件的纳米技术开辟一个新的舞台，如分子螺线管，分子电磁铁，分子发电机等。

Electronic properties of bucky tube modelled by a sheet of helical graphite cylinder named "grahelix" have been examined based on the one-dimensional tight-binding crystal orbital method in the framework of the Huckel approximation. It has been found that there are two types of grahelix depending on the helical pitch, that is, one is energetically stable and semiconductive whereas the other less stable with metallic nature.Moreover we elucidate that such metallic tubes are equivalent to those involving plural numbers of isolated cis-type polyacetylene skeletons arranged mostly in a helical manner on the tube surface. Such helical polyacetylene skeletons guarantee the metallic conduction path to the electrons near the Fermi level (spiralons). Control of the flow of these spiralons may open up a stage for nano-technology of the electronic devices such as molecular solenoid applicable to molecular electromagnet, molecular electric generator and so on.