Buckled carbon nanotube

A few months ago, Chuang and I discovered a new type of carbon nanotubes, when we were studying how to generate the helically coiled carbon nantoubes (HCCNTs) from toroidal carbon nanotubes (TCNTs).
In the following picture, I show a beaded model for a unit cell of the BCNT (bulged or buckled CNT) which has the same molecular graph as that of T120, but with different boundary condition.



From this picture, we can see that the trick for making this type of systems is to take the inner-rim (neck) of the TCNT out, and repeat this basic unit, the resulting structure is a BCNT.

Using this trick, we can easily see that there is a one-to-one correspondence between TCNT and BCNT.