Baughman, R. H. and D. S. Galv√£o (1993). "Tubulanes: carbon phases based on cross-linked fullerene tubules." Chemical Physics Letters 211(1): 110-118.

Structure and properties are calculated for five predicted carbon phases, called tubulanes, which are shown to be possible reaction products of single-layer and multiple-layer carbon tubules. Each carbon atom is equivalent and in a modified sp3 state in these phases which contain column structures that are directly related to those in either armchair or zig-zag carbon tubules. One such phase has a predicted bulk modulus which is within 6% of that of diamond, and a predicted heat of formation which is much lower than for either the C60 fullerene or other previously characterized no-diamond-like phases containing only sp3 carbons.

http://dx.doi.org/10.1016/0009-2614(93)80059-X