(A) Left axis: strain distribution in 3.8 nm-diameter CdTe nanocrystals capped with 6 monolayers of ZnSe shell. The solid black line indicates strain for the QDs modeled as concentric spheres, and the red hatched lines as concentric cylinders. Strain within the core is compressive and isotropic, while the strain in the shell is compressive in the radial direction (bottom line) and tensile in the tangential direction (top line). Right axis: Calculated lattice constants corresponding to strain profiles for strained, concentric, core/shell spheres and cylinders. The blue hatched line shows the observed lattice constant, determined from XRD and TEM. Blue indices on the axis depict the bulk lattice constants of CdTe (6.482 Å) and ZnSe (5.6676 Å). (B) The critical thickness (black line) is the shell thickness for which the formation of a dislocation loop is energetically more favorable than coherent, epitaxial growth for different core sizes and shell thicknesses.