The chemical bond as an emergent phenomenon.
The chemical bond as an emergent phenomenon.
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化学键作为一种新兴现象。
DOI：
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发表时间：
2017
影响因子：
4.4
通讯作者：
V. Lubchenko
中科院分区：
文献类型：
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作者：
J. C. Golden;Vinh Ho;V. Lubchenko
首先，我们认为共价键和各种闭壳层相互作用可以被认为是同一种相互作用的对称破缺版本，即，多中心键。我们使用特别选择的分子单元来表明对称性破缺是由密度和电负性变化控制的。我们发现，键序的变化与债券变形，但在一个步骤一样的方式，区域附近的恒定分离的电子本地化过渡。这些通常也会引起位移转变，从而使键强度、顺序和长度自洽地建立。我们进一步论证了共价、闭壳层和多中心相互作用与离子和金属键合的内在联系。所有这些相互作用可以被看作是不同的部门上的相图与密度和电负性的变化作为控制变量;离子和共价/二级部门与现场和键序电荷密度波，分别与金属部门的电子流体。虽然在低密度下显示出连续性，但金属和离子相互作用表示在足够高的密度下由不连续过渡分离的不同相。多中心相互作用表现为金属键和离子键的混合，这是离域电子和局域电子空间共存的结果。在本说明书中，化合物的稳定性的问题是具有不同程度的电子局域化的电子流体的相互兼容性，在复杂的无机化合物中自然产生的超原子有序。由此提出的电子定位的概念提出了一种高通量的自动化程序，用于筛选候选化合物和结构的稳定性，而不需要计算成本高的几何优化。
We first argue that the covalent bond and the various closed-shell interactions can be thought of as symmetry broken versions of one and the same interaction, viz., the multi-center bond. We use specially chosen molecular units to show that the symmetry breaking is controlled by density and electronegativity variation. We show that the bond order changes with bond deformation but in a step-like fashion, regions of near constancy separated by electronic localization transitions. These will often cause displacive transitions as well so that the bond strength, order, and length are established self-consistently. We further argue on the inherent relation of the covalent, closed-shell, and multi-center interactions with ionic and metallic bonding. All of these interactions can be viewed as distinct sectors on a phase diagram with density and electronegativity variation as control variables; the ionic and covalent/secondary sectors are associated with on-site and bond-order charge density wave, respectively, the metallic sector with an electronic fluid. While displaying a contiguity at low densities, the metallic and ionic interactions represent distinct phases separated by discontinuous transitions at sufficiently high densities. Multi-center interactions emerge as a hybrid of the metallic and ionic bond that results from spatial coexistence of delocalized and localized electrons. In the present description, the issue of the stability of a compound is that of the mutual miscibility of electronic fluids with distinct degrees of electron localization, supra-atomic ordering in complex inorganic compounds coming about naturally. The notions of electronic localization advanced hereby suggest a high throughput, automated procedure for screening candidate compounds and structures with regard to stability, without the need for computationally costly geometric optimization.