1. Theory and Simulation of Materials (THEOS), and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
2. Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 OFA, U.K.
3. Dipartimento di Scienze Fisiche, Informatiche e Matematiche, University of Modena and Reggio Emilia, IT-41125 Modena, Italy
4. Department of Quantum Matter Physics, University of Geneva, CH-1211 Genéve, Switzerland