Do all wurtzite nanotubes prefer faceted ones?

First-principles computations have been preformed to investigate the stability of one-dimensional (1D) crystalline nanowires, faceted nanotubes, and conventional single-walled nanotubes (SWNTs) with various sizes, as well as the two-dimensional infinitely single layers for several wurtzite materials. Regardless of the diameters, the SWNTs are more stable than sp(3)-dominated faceted nanotubes and nanowires for BN and C, while for AlN, GaN, ZnO, ZnS, and Si, the faceted nanotubes and nanowires are always more preferred energetically than SWNTs. However, the stability of SiC SWNTs relative to other 1D nanostructures is diameter-dependent: the SiC SWNTs are more stable than thinner faceted nanotubes and nanowires, but less stable than thick ones. This indicates that SiC SWNTs and faceted nanotubes/nanowires preserving wurtzite configuration can coexist in nanoscale. The different stabilities for various nanostructures are attributed to the competition between sp(2) and sp(3) hybridization of the atoms in wurtzite materials associated with the difference in the atomic radius and electronegativity of the elements involved.