  Linear nanotubular boron-carbon heterojunctions are systematically
constructed and studied with the help of ab initio total energy calculations.
The structural compatibility of the two classes of materials is shown, and a
simple recipe that determines all types of stable linear junctions is
illustrated in some detail. Our results also suggest the compatibility of
various technologically interesting types of nanotubular materials, leading to
novel types of nanotubular compound materials, and pointing out the possibility
of wiring nanotubular devices within heterogeneous nanotubular networks.
