Sagatova Dinara N, Gavryushkin Pavel N, Sagatov Nursultan E, Banaev Maksim V
Sobolev Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia.
Department of Geology and Geophysics, Novosibirsk State University, Novosibirsk, Russia.
J Comput Chem. 2023 Dec 15;44(32):2453-2460. doi: 10.1002/jcc.27210. Epub 2023 Aug 23.
In this study, we present the results of a search for new stable structures of SrC O and BaC O in the pressure range of 0-100 GPa based on the density functional theory and crystal structure prediction approaches. We have shown that the recently synthesized pyrocarbonate structure SrC O - is thermodynamically stable for both SrC O and BaC O . Thus, SrC O - is stable relative to decomposition reaction above 10 GPa, while the lower-pressure stability limit for BaC O - is 5 GPa, which is the lowest value for the formation of pyrocarbonates. For SrC O , the following polymorphic transitions were found with increasing pressure: at 40 GPa and 1000 K, at 90 GPa and 1000 K. SrC O - and SrC O - are characterized by the framework and layered structures of [CO ] tetrahedra, respectively. For BaC O , with increasing pressure, decomposition of BaC O - into BaCO and CO is observed at 34 GPa without any polymorphic transitions.
在本研究中，我们基于密度泛函理论和晶体结构预测方法，展示了在0 - 100 GPa压力范围内对SrCO和BaCO新稳定结构的搜索结果。我们已经表明，最近合成的焦碳酸盐结构SrCO - 对于SrCO和BaCO在热力学上都是稳定的。因此，SrCO - 在高于10 GPa时相对于分解反应是稳定的，而BaCO - 的低压稳定极限是5 GPa，这是形成焦碳酸盐的最低值。对于SrCO，随着压力增加发现了以下多晶型转变：在40 GPa和1000 K时，在90 GPa和1000 K时。SrCO - 和SrCO - 分别以[CO]四面体的骨架和层状结构为特征。对于BaCO，随着压力增加，在34 GPa时观察到BaCO - 分解为BaCO和CO，没有任何多晶型转变。
