The growth dynamics, and the ultimate electronic band structure-hence the physical properties-of self-assembled epitaxial semiconductor nanowires and dots depends on the strain states of epitaxial thin films, which are functions of composition, morphology, and relaxation. High-resolution X-ray reciprocal space mapping (RSM) provides a nondestructive, yet quantitative, technique for the characterization of the strain, composition, and morphology of multi-dimensional nanowire or nanodot arrays. Rigaku’s new Smartlab® automated diffractometer (Figure 1) makes reciprocal space mapping at medium, high, and very high resolution much easier and faster with minimal user interference.