Spin Density Topology
Spin Density Topology
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DOI：
10.3390/molecules25153537
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发表时间：
2020-08-01
期刊：
影响因子：
4.6
通讯作者：
Gatti, Carlo
中科院分区：
文献类型：
--
作者：
Bruno, Giovanna;Macetti, Giovanni;Gatti, Carlo
尽管它在自旋密度泛函理论中的作用，它是描述和理解磁现象的基本观测，但迄今为止，很少有研究出现在电子自旋密度的微妙之处。一个系统的完整的拓扑分析，这个功能是缺乏的，似乎在过去20年中的许多研究开花的其他标量场的化学兴趣的拓扑特征。我们的目标是通过揭示隐藏在自旋密度分布中的信息来填补这一空白，这些信息只有其拓扑结构才能揭示。自旋密度临界点的意义，18种不同的方式，它们可以实现和特有的拓扑约束，其数量和种类，所产生的存在下的积极和消极的自旋密度区域，是解决。介绍了分子自旋图、自旋极大（极小）点连接路径、自旋盆及其价态的概念。我们表明，两种结构与自旋极化分子：通常的一个，通过电子密度梯度定义，和themagneticstructure，通过自旋密度梯度定义，并组成一般至少有两个独立的自旋图，有关自旋密度的最大值和最小值。引入了自旋极化指数等描述子来表征自旋密度临界点和临界盆的性质。在研究自旋密度拓扑的一般特征之后，使用越来越精确的自旋密度分布，研究了处于（3）B（1）三重态的水分子的具体例子。
Despite its role in spin density functional theory and it being the basic observable for describing and understanding magnetic phenomena, few studies have appeared on the electron spin density subtleties thus far. A systematic full topological analysis of this function is lacking, seemingly in contrast to the blossoming in the last 20 years of many studies on the topological features of other scalar fields of chemical interest. We aim to fill this gap by unveiling the kind of information hidden in the spin density distribution that only its topology can disclose. The significance of the spin density critical points, the 18 different ways in which they can be realized and the peculiar topological constraints on their number and kind, arising from the presence of positive and negative spin density regions, is addressed. The notion of molecular spin graphs, spin maxima (minima) joining paths, spin basins and of theirvalenceis introduced. We show that two kinds of structures are associated with a spin-polarized molecule: the usual one, defined through the electron density gradient, and themagneticstructure, defined through the spin density gradient and composed in general by at least two independent spin graphs, related to spin density maxima and minima. Several descriptors, such as the spin polarization index, are introduced to characterize the properties of spin density critical points and basins. The study on the general features of the spin density topology is followed by the specific example of the water molecule in the(3)B(1)triplet state, using spin density distributions of increasing accuracy.