L.  Giacomazzi, Martin-Samos, L., Boukenter, A., Ouerdane, Y., Girard, S., and Richard, N., ?Ge(2), Ge(1) and Ge-E' centers in irradiated Ge-doped silica: A first-principles EPR study?, Optical Materials Express, vol. 5, pp. 1054-1064, 2015.