Synthetic single crystals of K[(Cu^II,Mn^II,Mn^III)₂(TeO₃)₃]·2H₂O were obtained from an overconcentrated alkaline aqueous solution in the system K₂O-MnO-CuO-TeO₂ under hydrothermal conditions at T ≤ 220 °C. Subeuhedral single crystals have been investigated by means of single-crystal X-ray diffraction. The crystal structure of this new zemannite-type representative adopts a monoclinic twofold superstructure. The doubling of the unit-cell volume is accompanied by a hexagonal-to-monoclinic symmetry reduction, resulting in threefold twinning with individual crystal domains following the space group symmetry P2₁. Refinements of site-occupation factors and the evaluation of bond valences suggest a distribution of di- and trivalent cations at the octahedrally coordinated M sites with a ratio (Cu^II + Mn^II):Mn^III approximating 1:1. Based on arguments about the cation sizes and the individual bond valence sums, a distribution of Cu^II_1–xMn^III_x and Mn^II_x Mn^III_1–x at each two of the four M sites can be assumed with x between ~ 0.14 and ~ 0.50. The K⁺ cations and H₂O molecules inside the channels are located off the central channel axis. In contrast to most other known zemannite-type phases, the extra-framework atoms show full occupancies and are not disordered. The distribution of the channel contents supports the anisotropic deformation of the surrounding framework, which follows the local symmetry reduction as required for the Jahn-Teller distortion of the octahedrally coordinated M sites within the framework. The arrangement of the deformed channels can be understood as the origin of the existing superstructure.

^{K[(Cu II} ,Mn ^II ,Mn ^III ) ₂ (TeO ₃ ) ₃ ]·2H ₂ O的合成单晶是在K ₂ O-MnO-CuO-TeO ₂体系中的超浓碱性水溶液中水热合成的。在T 的条件 ≤ 220 °C。已经通过单晶 X 射线衍射研究了亚自面体单晶。这种新的钙锰矿型代表的晶体结构采用单斜双重超结构。晶胞体积的加倍伴随着六方晶系到单斜晶系的对称性降低，导致具有遵循空间群对称性 P 2 1 的单个晶畴的三重孪_晶。位点占据因子的改进和键价的评估表明二价和三价阳离子在八面体配位的M位点分布，比例为 (Cu ^II  + Mn ^II ):Mn ^III近似于 1:1。基于关于阳离子大小和单个键价总和的论点，可以假设Cu ^II _{1– x} Mn ^III _x和 Mn ^II _x Mn ^III _{1– x}在四个M位中的每两个处的分布，其中x在 ~ 0.14 之间和 ~ 0.50。K ⁺阳离子和H ₂通道内的 O 分子位于通道中心轴之外。与大多数其他已知的锌锰矿型相相比，骨架外的原子显示出完全占据并且没有无序。通道内容物的分布支持周围框架的各向异性变形，这遵循框架内八面体配位M位点的 Jahn-Teller 畸变所需的局部对称性减少。变形通道的布置可以理解为现有上层建筑的起源。