I just finished writing the section on the influence of endcaps on the nanotube's shape in my "The beaded molecules I. Spheroids" paper. I put my emphasis on (5,5) and (9,0) SWNT with the C60 endcaps, which is fine. I thought there should be a more systematic study on the effect of endcaps from the beaded molecule's viewpoints. This should include the patching conditions, chiral nanotubes and the effect on the shape change. I have no doubt that many of the issues I raised here probably have been treated before. I still think it is worthy to do it with the beaded molecules.