Burbank R D, Jones G R
Science. 1971 Feb 5;171(3970):485-7. doi: 10.1126/science.171.3970.485.
Three crystalline phases of xenon hexafluoride are based on tetrameric association of XeF(5)(+) and F(-) ions into eight-membered rings. Phase I (monoclinic, 8 XeF(6) units per cell) transforms at approximately 10 degrees C to phase II (orthorhombic, 16 XeF(6) units per cell), which in turn transforms at approximately -25 degrees C to phase 111 (monoclinic, 64 XeF(6) units per doubly primitive cell). The transformation from phase I to phase II requires gross reorientation of half of the tetramers in the structure. The transformation from phase II to phase III involves only an ordering of right-handed and left-handed configurations.
六氟化氙的三种晶相基于XeF₅⁺和F⁻离子通过四聚体缔合形成八元环。I相（单斜晶系，每个晶胞含8个XeF₆单元）在约10℃时转变为II相（正交晶系，每个晶胞含16个XeF₆单元），而II相又在约 -25℃时转变为III相（单斜晶系，每个双原胞含64个XeF₆单元）。从I相到II相的转变需要结构中一半的四聚体进行大幅重新取向。从II相到III相的转变仅涉及右手构型和左手构型的有序排列。
