1. Department of Mathematical Sciences, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italy
2. Centre Européen de Calcul Atomique et Moléculaire (CECAM), École Polytechnique Fédérale de Lausanne, Batochime, Avenue Forel 2, 1015 Lausanne, Switzerland
3. Institute for Applied Computing “Mauro Picone” (IAC), CNR Via dei Taurini 19, 00185 Rome, Italy