Two types of meta-crystals for IV group elements: Density functional theory calculations

Using density function theory (DFT) implemented in VASP package, we find two new type of meta-crystals constructed by IV group elements: Si-568 and Ge-568. The calculational results show that Si-568 has a band gap of 0.09 eV estimated by DFT, while Ge-568 behaves metallic. These two new types of nano-structures both can be created via experimentally observed di-vacancies (DVs) and Stone–Thrower–Wales (STW) defect.