Ultrahigh-resolution transmission electron microscopy nowadays enables inter-atomic distances in materials to be measured with an accuracy of a few picometres. A picometre is approximately one hundred times smaller than the diameter of an atom. In this way, it is possible to identify the decisive parameters that determine the physical properties of materials directly on the atomic level in a transmission electron microscope. Such studies are only possible at a few locations in the world. The Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons in Forschungszentrum Jülich is one of the pioneers in this area of research.