For four decades fairbankite was reported to have the formula Pb2+(Te4+O3), but repeated attempts to isolate fairbankite crystals for structural determination found only the visually similar cerussite and, more rarely, anglesite. The crystal-structure determination of fairbankite using single-crystal X-ray diffraction, supported by electron microprobe analysis and X-ray powder diffraction on the type specimen, has shown that fairbankite contains essential S, along with Pb, Te, and O. The chemical formula of fairbankite has been revised to Pb122+(Te4+O3)11(SO4). This change has been accepted by the IMA–CNMNC, Proposal 19-I. The crystal structure of fairbankite [space group P1 (no. 1); revised cell: a = 7.0205(3) Å, b = 10.6828(6) Å, c = 14.4916(8) Å, a = 75.161(5)°, b = 81.571(4)°, g = 83.744(4)°, V = 1036.35(9) Å3, and Z = 1] is the first atomic arrangement known to contain a Te34+O96− non-cyclic, finite building unit. Fairbankite has an average structure, formed from a 3D framework of Pb2+On polyhedra, Te4+On polyhedra, and SO4 tetrahedra in a 12:11:1 ratio. The stereoactive lone pairs of the Pb2+ and Te4+ cations are oriented into void space within the structure. Fairbankite contains two mixed sites statistically occupied by Te4+ and S6+ in approximately 4:1 and 1:4 ratios. These two sites possess Te4+ in trigonal-pyramidal environment and S6+ in tetrahedral environment (with an additional O site to create tetrahedral SO4 shape for the S-dominant site). Six of the 10 fully occupied Te4+ sites have Te4+ in trigonal-pyramidal environment, while four have Te4+ at the center of highly distorted Te4+O4 disphenoids. The disphenoids allow for the creation of two dimeric Te24+O64− units in addition to the Te34+O96− trimeric unit, which contains two disphenoids. All linkage between disphenoids and trigonal pyramids is via corner-linking. Secondary connectivity is via long Te–O and Pb–O bonds.

中文翻译：

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阐明Pb2 + Te4 + O3的自然-合成失配：将白铁矿重新定义为Pb122 +（Te4 + O3）11（SO4）

据报道，四十年来，白铁矿的分子式为Pb2 +（Te4 + O3），但反复尝试分离白铁矿晶体进行结构测定，发现仅在外观上类似的铜铁矿，而很少是角铁矿。使用单晶X射线衍射，电子显微探针分析和X射线粉末衍射对类型标本进行测定，确定白云母的晶体结构表明，白云母含有必需的S以及Pb，Te和O。白铁矿的化学式已修改为Pb122 +（Te4 + O3）11（SO4）。IMA–CNMNC建议19-I接受了此更改。白云母的晶体结构[空间群P1（1号）；修正单元格：a = 7.0205（3）Å，b = 10.6828（6）Å，c = 14.4916（8）Å，a = 75.161（5）°，b = 81.571（4）°，g = 83.744（4）° ，V = 1036.35（9）Å3，[Z = 1]是已知的第一个包含Te34 + O96-非环状有限构建单元的原子排列。飞石具有由Pb2 + On多面体，Te4 + On多面体和SO4四面体的3D框架以12：11：1的比率形成的平均结构。Pb2 +和Te4 +阳离子的立体孤对被定向到结构内的空隙空间中。Fairbankite包含两个混合位置，据统计，它们分别以大约4：1和1：4的比例被Te4 +和S6 +占据。这两个位点在三角锥体环境中具有Te4 +，在四面体环境中具有S6 +（具有一个额外的O位以为S主导位点产生四面体SO4形状）。10个完全占据的Te4 +站点中的六个在三角锥环境中具有Te4 +，而四个在高度扭曲的Te4 + O4蝶形体的中心处具有Te4 +。除了包含两个蝶形体的Te34 + O96-三聚体单元以外，双蝶形体还允许创建两个二聚体Te24 + O64-单元。蝶形和三角锥之间的所有链接都是通过角链接。二级连接是通过长的Te-O和Pb-O键实现的。