Basel University : Smallest Swiss Cross – Made of 20 Single Atoms ( a NANOSENSORS PPP-NCL was used for this image)
20 bromine atoms positioned on a sodium chloride surface using the tip of an atomic force microscope at room temperature, creating a Swiss cross with the size of 5.6nm. The structure is stable at room temperature and was achieved by exchanging chlorine with bromine atoms. (Fig: University of Basel, Department of Physics)