Mo6S6 nanowires: structural, mechanical and electronic properties

The properties of nanowires were investigated with ab initio calculations based on the density-functional theory. The molecules build weakly coupled one-dimensional chains, like and Mo₆S_9-xI_x, and the crystals are strongly uniaxial in their mechanical and electronic properties. The calculated moduli of elasticity and resilience along the chain axis are c₁₁ = 320 GPa and E_R = 0.53 GPa, respectively. The electronic band structure and optical conductivity indicate that the crystals are good quasi-one-dimensional conductors. The frequency-dependent complex dielectric tensor ε, calculated in the random-phase approximation, shows a strong Drude peak in ε_∥, i.e., for the electric field polarised parallel to the chain axis, and several peaks related to interband transitions. The electron energy loss spectrum is weakly anisotropic and has a strong peak at the plasma frequency ħω_p ≈20 eV. The stability analysis shows that is metastable against the formation of the layered .