Abstract

Crystals of a new complex layered lead carbonate silicate Pb_19.4Na_1.9[Si₁₀O₂₅](CO₃)₉(OH)_12.7 ⋅ 1.3H₂O and lead silicogermanate Pb_4.37[(Ge_0.7Si_0.3)₂O₇][(Ge_0.6Si_0.4)O_2.74(OH)_1.26], related to ganomalite, were prepared by the hydrothermal synthesis route. The compounds crystallize in sp. gr. P31m and P\(\bar {6}\), respectively. The new compounds, like many lead silicates and silicogermanates, are characterized by disorder, wide isomorphism, defects at sites occupied by large cations, and isomorphous substitutions of Ge and Si atoms in tetrahedra. The similarity and difference of new lead compounds compared to those studied previously were revealed in terms of the traditional crystal-chemical theory and the topology and symmetry analysis of structures. The structural relationships `for the plumbonacrite–new carbonate silicate–synthetic lead borate silicate and apatite–nasonite–ganomalite–synthetic lead silicate series are described. The polytypic nature and homologous series were revealed. The alphabetic notation is proposed to describe the symmetry laws of structures.

中文翻译：

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新型硅酸铅：结构与拓扑及对称性分析

摘要

一个新的复杂的层状碳酸铅硅酸盐铅晶体_19.4钠_1.9 [硅₁₀ ø ₂₅ ]（CO ₃）₉（OH）_12.7 ⋅1.3H ₂ O和铅silicogermanate铅_4.37 [（葛_0.7的Si _0.3）₂ ö ₇ ] [通过水热合成法制备了与硅锰矿有关的（Ge _0.6 Si _0.4）O _2.74（OH）_1.26 ]。该化合物在sp中结晶。gr。P 31 m和P \（\ bar {6} \）， 分别。像许多硅酸铅和硅锗酸铅一样，新化合物的特征是无序，同质性广，被大阳离子占据的位点处的缺陷以及四面体中Ge和Si原子的同构取代。通过传统的晶体化学理论以及结构的拓扑和对称性分析，揭示了新铅化合物与先前研究的化合物的相似性和差异性。描述了铅锌矿-新碳酸盐硅酸盐-合成硼酸铅硅酸盐和磷灰石-钠铁矿-铅锌矿-合成硅酸铅系列的结构关系。揭示了多型性和同源序列。提出了字母符号来描述结构的对称律。