  A two-dimensional scandium carbide monolayer with a Sc3C10 primitive cell
(Sc3C10 sheet) has been identified using first-principles density functional
theory. In the Sc3C10 sheet, there is a similar basic structure to the one in
the Volleyballene Sc20C60, the Sc8C10 subunit, in which two connected carbon
pentagons are surrounded by one scandium octagon. The hybridization between Sc
d orbitals and C s-p orbitals is crucial for stabilizing the Sc3C10 sheet. Ab
initio molecular dynamics simulations demonstrate that this Sc3C10 sheet is
exceptionally stable. In addition, a series of stable ScC nanotubes have been
obtained by rolling up this Sc3C10 sheet. All nanotubes studied have been found
to be metallic.
