Ab initio prediction of metallic nature of sp3-hybridized germanium structures

Guided by Density Functional Theory within the bounds of GGA/PBE theory, we study the electronic, energy, mechanical and ballistic conductivity of germanium [n,m]-prismanes. The prismatic structure is a cylinder, with a m-vertices polygon (germanium ring) at the foot and an n-number of such polygons along the growth direction of the nanotube. As depicted, the finite prismanes reduce their band gap with an increase in the number of rings and periodic systems have metallic conductivity. It is established that metallic properties are resistant to the stress applied along the main axis of the prismanes.