Atomic structure and energetic stability of complex chiral silicon nanowires

Avramov, P.; Minami, Soma*; Irle, S.*; Chernozatonskii, L. A.*; Morokuma, Keiji*

Atomic and electronic structure and energetic stability of newly proposed pentagonal and hexagonal chiral complex silicon nanowires (NWs) composed of five or six 1 1 0 oriented crystalline fragments were studied using the ab initio DFT method. The chirality of the wires was caused by consecutive shifts of each fragment by 1/5 or 1/6 of the wire unit cell parameter and rotations of 4 and 3.3 for achiral pentagonal or hexagonal wires, respectively. Chirality causes the HOMO-LUMO gap to reduce by 0.1 eV. Chiral silicon nanowires are found to be metastable structures with a 4.5 (kcal/mol)/Si atom potential barrier for reversible chiral achiral transformation.