We report a systematic study of the thermal and mechanical properties of 134 pure SiO2 zeolites through DFT-based calculations by making use of the quasi-harmonic approximation (out of a total of 242 known fully ordered zeolitic frameworks). The comparison of our results with reported experimental data for several zeolites revealed a very good accuracy and validated our simulation methodology. We observe a wide range of thermal expansion coefficients (from −5 to −35 MK−1), highlighting the great influence of the framework topology over this physical property, while demonstrating that all pure-silica zeolites exhibit negative thermal expansion (NTE). Our simulations also provide a path for the computation of the bulk modulus for each structure, as well as its pressure and temperature dependence. Results revealed a large gamut of bulk modulus values (from 8 to 134 GPa), showing that most frameworks display pressure-induced softening — but not all! Finally, this study provides some hints to the open question of experimental feasibility of zeolitic frameworks, showing that the experimentally synthesized structures appear to have a distinct distribution of thermal and mechanical properties.

中文翻译：

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沸石骨架热性能的系统研究

我们通过使用准谐波近似（总共242种已知的全序沸石骨架中），通过基于DFT的计算，对134种纯SiO2沸石的热和机械性能进行了系统的研究。将我们的结果与几种沸石的实验数据进行比较，结果显示出非常好的准确性，并验证了我们的模拟方法。我们观察到了广泛的热膨胀系数（从-5到-35 MK-1），强调了骨架拓扑结构对该物理性质的巨大影响，同时证明了所有纯硅沸石均表现出负热膨胀（NTE）。我们的仿真还为每种结构的体积模量及其压力和温度依赖性的计算提供了一条路径。结果显示了很大的体积模量值范围（从8 GPa到134 GPa），表明大多数框架都显示出压力引起的软化-但并非全部！最后，本研究为沸石骨架实验可行性的开放性问题提供了一些提示，表明实验合成的结构似乎具有明显的热和机械性能分布。