I am working on a structure consisting of a network of inter-penetrating carbon nanotubes that are perpendicular to each other. Only four unit cells are done currently. Hopefully I can finish the next four unit cells in next few weeks.
This structure is very similar to the one posted in
"Pseudo P-type carbon Schwartzite", except that I inserted a segment of carbon nanotubes in between each two nearest-neighbored junctions. Three mutually perpendicular carbon nanotubes meet at a junction that contains 24 heptagons. Moreover, one can also easily identify eight monkey saddles at each junction.