Properties of C60 and related compounds

基于一维紧束缚晶体轨道方法，在Huckel近似的框架下，研究了由一层名为“Grahelix”的螺旋石墨圆柱体模拟的巴基管的电子性质。根据螺距的不同，存在两种类型的螺旋，一种是能量稳定的半导体型，另一种是较不稳定的金属性质的，并阐明了这种金属管相当于由多个孤立的顺式聚乙炔骨架组成的金属管，这些骨架大多以螺旋方式排列在管子表面。这种螺旋聚乙炔骨架保证了到费米能级附近的电子(螺旋子)的金属传导路径。对螺旋管流量的控制可以为分子电磁铁、分子发电机等电子器件的纳米技术开辟一个舞台。

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.