The cover image shows an atomic scale simulation of the electron distribution in an InAs/GaAs quantum dot. Different colors represent the charge densities on different atoms in the quantum dot. Quantum dot computation and visualization is a collaborative research project between staff in NIST’s Physics Laboratory and NIST’s Information Technology described in this issue (p. 131). The cover image was generated by Howard K. Hung and Steven G. Satterfield of the Scientific Applications and Visualization Group in ITL using the NIST immersive environment. Cover arranged by C. Carey.