1. Department
of Chemical Sciences, University of Padova, via Marzolo 1, Padova 35131, Italy
2. Department
of Materials Science and Engineering and Center for 2-Dimensional
and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
3. CNR-IOM, TASC
Laboratory, AREA Science
Park Basovizza, 34149 Trieste, Italy
4. International Centre for Theoretical Physics, Strada Costiera 11, 34100 Trieste, Italy