Synthesis and Properties of the Helium Clathrate and Defect Perovskite [He2–x□x][CaNb]F6

Shangye Ma, Brett R. Hester, Anthony J. Lloyd II, Antonio M. dos Santos, Jamie J. Molaison, and Angus P. Wilkinson, Synthesis and Properties of the Helium Clathrate and Defect Perovskite [He_2–x□_x][CaNb]F₆, The Journal of Physical Chemistry C