Vatamanu Jenel, Kusalik Peter G
Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4.
J Am Chem Soc. 2006 Dec 13;128(49):15588-9. doi: 10.1021/ja066515t.
We present previously unreported crystalline and polycrystalline structures for methane hydrates obtained at relatively low pressures. These structures, which contain unusual cages with 12 pentagonal faces and 3 hexagonal faces, were observed during the atomistic simulations of the crystal growth of sI and sII methane hydrates. These 51263 cages have a significant impact on the structure of the resulting crystal and could explain several experimental observations regarding in-situ transformations between sI and sII hydrates. We document a previously unidentified structure of methane hydrates which we designate structure sK. Additionally, we predict a polycrystalline structure consisting of this new hydrate and sI and suggest a mechanism for the formation of a polycrystalline structure consisting of sequences of sI and sII hydrates.
我们展示了在相对低压下获得的甲烷水合物的先前未报道的晶体和多晶结构。这些结构包含具有12个五边形面和3个六边形面的异常笼状结构，在sI和sII型甲烷水合物晶体生长的原子模拟过程中被观察到。这些51263笼对所得晶体的结构有重大影响，并可以解释关于sI和sII水合物之间原位转变的几个实验观察结果。我们记录了一种先前未识别的甲烷水合物结构，我们将其指定为sK结构。此外，我们预测了一种由这种新水合物和sI组成的多晶结构，并提出了一种由sI和sII水合物序列组成的多晶结构的形成机制。
