A new class of MO2 dioxide nanotubes (M=Si, Ge, Sn, Pb) composed of “square” lattices of atoms: Their structure and energy characteristics

New dioxide nanotubes are described. These nanotubes are rolled up of a “square” lattice of atoms differing from the conventional hexagonal lattice isoelectronic to graphite. The dependence of the strain energy on the nanotube diameter D departs from a 1/D ² behavior, and the optimum shape at the same diameter corresponds to “zigzag” tubelenes. Two-layer nanotubes consisting of an MO₂ layer bonded to a carbon nanotube (CNT) are characterized by a considerably lower strain energy, which points to the possibility of using CNTs as a template for the synthesis of such MO₂ nanotubes.