Cubic structure II (CS-II) Ar hydrate.
Paulo H. B. Brant Carvalho, Amber Mace, Ove Andersson, Chris A. Tulk, Jamie Molaison, Alexander P. Lyubartsev, Inna M. Nangoi, Alexandre A. Leitão, and Ulrich Häussermann, Pressure-induced amorphization of noble gas clathrate hydrates. Phys. Rev. B, 103 (2021).