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Nature of chemical bond in view of electron density distributions and a new expression for cohesive mechanism between atoms in metalcompounds

从电子密度分布来看化学键的性质以及金属化合物中原子间内聚机制的新表达

基本信息

批准号：
14205091
负责人：
MORINAGA Masahiko
金额：
$ 25.21万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14205091/
关键词：
chemical bond electronic structure molecular orbital method electron density metal compounds oxides covalent bond ionic bond

项目摘要

Knowledge of spatial electron density distribution, p(r), is so fundamental for the full understanding of the nature of the chemical bond between atoms in matter. For convenience, several methods have been proposed for analyzing p(r). For example, following the Mulliken population analysis method, overlap populations and orbital populations are calculated and used as a measure of chemical interactions between atoms. Such interactions may be also characterized by the Laplacian of the electron density, ▽^2 p(r). However, despite great efforts, there has been little information of the feature of p(r) common to every matter. Here, we show a universal relation between electron density minima, p_<min> and atomic or ionic radii, r_<min>, which was discovered from the first principles DV-Xα molecular orbital calculations of electronic structures in matter over 150 species, including gasses(H_2,O_2), water(H_2O), diamond(C), metals(Fe,Al), semi-conductors(Si,Ge), oxides(MgO,Al_2O_3,SiO_2,BaTiO_3), alkali halide crystals (NaCl,KCl), and metal compounds (TiC,ZrN). The universal relation was expressed as,log[p_<min>/Z^3]=-5.29 log[1.01+0.285x 2(Z/n)r_<min>].Here, Z is the atomic number of element and n is a principal quantum number. This relation provides us a clue to the understanding of the nature of chemical bond in matter in a fundamental manner.

空间电子密度分布p（r）的知识对于充分理解物质中原子之间的化学键的性质是非常重要的。为了方便起见，已经提出了几种分析p（r）的方法。例如，根据Mulliken布居分析方法，计算重叠布居和轨道布居，并将其用作原子之间化学相互作用的量度。这种相互作用也可以用电子密度的拉普拉斯算子来表征，即ε ^2 p（r）。然而，尽管付出了巨大的努力，几乎没有任何资料的特点，p（r）共同的每一个问题。本文给出了电子密度最小值p_<min>与原子或离子半径r_<min>之间的普遍关系，这是通过对包括气体（H_2，O_2）、水（H_2O）、金刚石（C）、金属（Fe，Al）、半导体（Si，Ge）、氧化物（MgO，Al_2O_3，SiO_2，BaTiO_3）、碱金属卤化物晶体（NaCl，KCl）和金属化合物（TiC，ZrN）在内的150多种物质的电子结构的第一性原理DV-Xα分子轨道计算发现的。普适关系式为log[p_<min>/Z^3]=-5.29 log[1.01+ 0.285x2（Z/n）r_<min>]，其中Z是元素的原子序数，n是主量子数。这种关系为我们从根本上理解物质中化学键的性质提供了线索。