Atomic Configuration of Nucleation (image) University of Pennsylvania Caption Atomic configuration of nucleation (blue atom group) in the surface layer of a square copper nanowire (yellow and green atoms) under uniaxial stress. Nucleation occurs at a partial dislocation in the surface layer. Colors refer to the breaking of local inversion symmetry. Credit Physical Review Letters and Ju Li, Department of Materials Science in the School of Engineering and Applied Science at Penn. Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.