On the existence and stability of single walled SiGe nanotubes

A systematic hybrid density functional theoretical study of three different types of single walled SiGe nanotubes in armchair (n, n) and zigzag (n, 0) (3 <= n <= 11) configurations is presented. The nanotubes have been represented by finite clusters with the dangling bonds saturated by hydrogen atoms. All structures have been both geometry and spin optimized without any symmetry constraints. Stability trend differs among armchair and zigzag nanotubes for the three different types. However, all SiGe nanotubes are semiconducting in nature, with a wide spectrum of band gaps. (C) 2008 Elsevier B. V. All rights reserved.