The intermetallic ytterbium compound Yb2Pd2Cd shows a structural phase transition at ∼150 K. The structures of the room-temperature (Mo2B2Fe type, P4/mbm, a = 757.07(7), c = 371.99(4) pm, wR2 = 0.0620, 272 F 2 values, 12 variables) and low-temperature (new type, P4/mbm, a = 747.26(4), c = 741.46(4) pm, wR2 = 0.0384, 511 F 2 values, 19 variables) modifications were refined from single crystal X-ray diffractometer data. The superstructure formation corresponds to an isomorphic transition of index 2. The driving force for the structural phase transition is an ytterbium charge ordering (the superstructure exhibits two crystallographically independent ytterbium sites) with a much higher degree of divalent ytterbium in the low-temperature modification. The striking structural feature concerns the ytterbium–palladium coordination with different Yb–Pd distances: longer ones for predominantly divalent Yb1 (2 × 284.7 and 4 × 296.1 pm, ∅ = 292.3 pm) and shorter ones for trivalent Yb2 (2 × 277.5 and 4 × 288.4 pm, ∅ = 284.8 pm).

中文翻译：

---

Yb2Pd2Cd 低温超结构中的镱价态有序性

金属间镱化合物Yb2钯2Cd 在 ∼150 K 时表现出结构相变。室温 (Mo2乙2铁型、磷4/MBM,A= 757.07(7),C= 371.99(4) 下午，WR2 = 0.0620, 272F 2值，12 个变量）和低温（新型，磷4/MBM,A= 747.26(4),C= 741.46(4) 下午,WR2 = 0.0384, 511F 2值，19 个变量）的修改是根据单晶 X 射线衍射仪数据进行细化的。上层建筑的形成对应于同构指数2的转变。结构相变的驱动力是镱电荷排序（超结构表现出两个晶体学上独立的镱位点），在低温改性中二价镱的程度要高得多。显着的结构特征涉及具有不同 Yb-Pd 距离的镱-钯配位：主要是二价 Yb1 的较长距离（2 × 284.7 和 4 × 296.1 pm，∅ = 292.3 pm），而三价 Yb2 的较短距离（2 × 277.5 和 4 × 288.4 下午，∅ = 284.8 下午）。