The experimental characterization of various dioctahedral smectites reveals weak correlations between the ratio of cis- and trans-vacant layer structures, fraction of charge in the tetrahedral sheet, and iron content. These correlations are demonstrated by two independent sample sets examined in different laboratories and, hence, are considered to be significant. For these relations to be rationalized and corroborated, accurate relative energies and ion exchange energies of a set of model minerals were determined by quantum chemical density functional calculations. Accordingly, one may trace these empirical correlations mainly back to energy relations and rationalize some deviating smectites by their particular history of formation.

中文翻译：

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八面体蒙脱石的晶体化学组成：基于能量的经验关系评估

对各种八面体蒙脱石的实验表征揭示了顺空结构和反空结构的比率，四面体板料中的电荷分数和铁含量之间的弱相关性。这些相关性通过在不同实验室中检验的两个独立样本集得到证明，因此被认为具有重要意义。为了使这些关系合理化和得到证实，通过量子化学密度函数计算确定了一组模型矿物的准确相对能量和离子交换能量。因此，人们可以将这些经验相关性主要追溯到能量关系，并通过它们的特殊形成历史合理化一些偏离的蒙脱石。