High-pressure polymorphs of ZnCO₃: evolutionary crystal structure prediction.
High-pressure polymorphs of ZnCO₃: evolutionary crystal structure prediction.
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ZnCO₃ 的高压多晶型物：演化晶体结构预测。
DOI：
10.1038/srep05172
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发表时间：
2014-06-04
影响因子：
4.6
通讯作者：
Zaoui A
中科院分区：
文献类型：
--
作者：
Bouibes A;Zaoui A
采用密度泛函理论和普适结构预测方法研究了ZnCO 3的高压行为。为了探索压力下所有可能的结构，在高压下进行了单独的计算，在单位晶胞中增加了公式单元的数量。考虑了两种压力诱导的相变。第一个发生在78 GPa，第二个发生在121 GPa。 最稳定的ZnCO 3在环境条件下对应的空间群R-3c（相I），这是在有利的协议与实验。在78 ~ 121 GPa压力范围内，C2/m空间群的结构（II相）趋于稳定。 最后，当压力达到121 GPa时，具有空间群P212121的结构（相III）变得最稳定。 计算了R-3c结构的一些力学性能，并与实验和前人的理论数据进行了比较。由此产生的行为支持我们的研究结果，并确认所获得的相变。此外，从电子电荷密度的分析来看，在78 GPa下，氧和锌之间形成了新的键，这可能是相变背后的主要原因。
The high-pressure behavior of zinc carbonate ZnCO3 has been investigated using universal structure prediction method together with the density functional theory. In order to explore all possible structures under pressure, separate calculations at high pressure are done here with increasing number of formula units in the unit cell. Two pressures induced phase transitions were considered. The first one occurs at 78 GPa and the second one at 121 GPa. The most stable ZnCO3 at ambient condition corresponds to the space group R-3c (phase I), which is in favorable agreement with experiment. The structure with C2/m space group (phase II) becomes stable between 78 GPa and 121 GPa. Finally, the structure with the space group P212121 (phase III) becomes the most stable when the pressure achieves 121 GPa. Some mechanical properties of R-3c structure were –additionally- calculated and compared with the experimental and previous theoretical data. The resulting behaviors support our findings and confirm the obtained phase transition. Besides, from the analysis of the electronic charge density it comes that at 78 GPa, new bond between oxygen and zinc is formed, what is likely the main cause behind the phase transition.