The current work is concentrated on the developing of the methodology for determining the size, shape and structure of nanoparticles, and has a great impact on metrology and quality control. The technique of creating the nanodiamond computer models has been successfully developed which allows modeling nanodiamonds of different shape and morphology including core@shell type hybrids. This approach also characterizes the nanoparticles comparing the experimental diffraction data and simulated XRD patterns. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.