1. Institut für Chemie und Biochemie Physikalische und Theoretische Chemie Freie Universität Berlin Arnimallee 22 14195 Berlin Germany
2. CNR Institute for Microelectronics and Microsystems (CNR‐IMM) Strada VIII, 5 Catania 95121 Italy
3. Computing Center Technical University of Denmark Kongens Lyngby DK‐2800 Denmark
4. Department of Physics Technical University of Denmark and Center for Nanostructured Graphene (CNG) Kongens Lyngby DK‐2800 Denmark