Energy landscapes, structural topologies and rearrangement mechanisms in clusters of dipolar particles
Energy landscapes, structural topologies and rearrangement mechanisms in clusters of dipolar particles
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DOI：
10.1039/c3sm50711d
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发表时间：
2013-04
期刊：
影响因子：
3.4
通讯作者：
J. Farrell;Christabel Lines;J. Shepherd;D. Chakrabarti;Mark A. Miller;D. Wales
中科院分区：
文献类型：
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作者：
J. Farrell;Christabel Lines;J. Shepherd;D. Chakrabarti;Mark A. Miller;D. Wales
具有各向同性吸引的球形粒子簇有利于结构紧凑，从而最大限度地增加能量最优的近邻相互作用的数量。相反，偶极相互作用导致形成配位数较低的链。当各向同性和偶极相互作用都存在时，它们之间的竞争会导致复杂的结、链和线圈结构。在这里，我们研究了这些结构如何在由斯托克迈尔势(Lennard-Jones加点偶极子)约束的簇中自组织和相互转换。我们使用不连通性图绘制出能量景观的低洼区域，以跟踪它如何随着偶极相互作用强度的增加而演变。通过对异构化途径的全面考察，我们确定了一些重排机制，这些重排机制允许链状结构的拓扑相互转化。
Clusters of spherical particles with isotropic attraction favour compact structures that maximise the number of energetically optimal nearest-neighbour interactions. In contrast, dipolar interactions lead to the formation of chains with a low coordination number. When both isotropic and dipolar interactions are present, the competition between them can lead to intricate knot, link and coil structures. Here, we investigate how these structures may self-organise and interconvert in clusters bound by the Stockmayer potential (Lennard-Jones plus point dipole). We map out the low-lying region of the energy landscape using disconnectivity graphs to follow how it evolves as the strength of the dipolar interactions increases. From comprehensive surveys of isomerisation pathways, we identify a number of rearrangement mechanisms that allow the topology of chain-like structures to interconvert.