Accurate Structure Determination of Mo6SyIz Nanowires from Atomic Pair Distribution Function (PDF) Analysis

The structure of the recently discovered systematically reproducible Mo 6 S y I z nanowires has been determined from the atomic pair distribution function (PDF) analysis of powder X-ray diffraction data. This total scattering approach was required because the nanowires are not perfectly crystalline and, therefore, the structure cannot be obtained crystallographically. Several nanotube and nanowire models were fit to the PDF data. The resulting best-fit model structure consists of nanowires of Mo 6 octahedra that are bridged by sulfur and terminated on the outside by iodine. This demonstrates the power of total scattering methods in accurately resolving structural issues in nanostructured materials where traditional crystallographic methods fail.