AM_Rubidium_4 Formula: Rb Name: Rubidium Unit cell: 5.612 5.612 5.612 90.0 90.0 90.0 , V=176.75 Space group: IM3M (229)

Kelly F M , Pearson W B , Canadian Journal of Physics , 33 (1955) p.17-24, The rubidium transition at ~180 K, Locality: synthetic, Sample: at T = 77 K, Note: specimen III