Using a list of compatible hydrate/anhydrate pairs prepared by van de Streek and Motherwell [CrystEngComm (2007), 9, 55–64], we have examined the effective volume per water of crystallization for 179 pairs of organic solids using current data from the Cambridge Crystallographic Structural Database (CSD). The effective volume is the difference per water molecule between the asymmetric unit volumes of the hydrate and parent anhydrate, and has the mean value 24 ų. The conformational changes in the reference molecule between the hydrate and its anhydrate are shown in two figures: one for a relatively rigid standard organic molecule and (in the supplementary file) one for a more flexible linear molecule. Using data from Nyman and Day [Phys. Chem. Chem. Phys. (2016), 18, 31132–31143], we have also established a generic volumetric coefficient of thermal expansion of organic solids with a value of 147 ± 56 × 10⁻⁶ K⁻¹. There is a significant number of outliers to the data, negative, near zero, and large and positive. Some explanation for the existence of these outliers is attempted.

中文翻译：

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结晶水的有效体积：一般有机固体。

使用兼容的水合物的列表/无水物对制备由van德Streek和马瑟韦尔[ CrystEngComm（2007），9，55-64]，我们已经研究每结晶水的有效容积179对使用从当前数据有机固体剑桥晶体结构数据库（CSD）。的有效体积是水合物和无水母体的不对称单元的体积之间每水分子的差，并且具有平均值24埃³。水合物与其无水合物之间参考分子的构象变化显示在两个图中：一个用于相对刚性的标准有机分子，（在补充文件中）一个用于更柔韧的线性分子。使用Nyman和Day的数据[物理 化学 化学 物理 （2016），18，31132-31143]，我们还建立的有机固体的热膨胀的通用体积系数与147±56×10的值^-6  ķ ^-1。数据存在大量异常值，包括负值，接近零值以及正值和零值。试图对这些异常值的存在进行一些解释。