Sadjadi SeyedAbdolreza, Matta Chérif F, Hamilton Ian P
Department of Physics, Faculty of Science, Laboratory for Space Research, The University of Hong Kong, Hong Kong SAR, China.
Department of Chemistry and Physics, Mount Saint Vincent University, Halifax, Nova Scotia, Canada.
J Comput Chem. 2021 Jan 5;42(1):40-49. doi: 10.1002/jcc.26431. Epub 2020 Oct 16.
Electronic structure and bonding properties of the Group 12 dications M (M = Zn, Cd, Hg) are investigated and electron density-derived quantities are used to characterize the metastability of these species. Of particular interest are the complementary descriptions afforded by the Laplacian of the electron density ∇ ρ(r) and the one-electron Bohm quantum potential (Q = ) along the bond path. Further, properties derived from the pair density including the localization-delocalization matrices (LDMs) and the interacting quantum atoms (IQA) energies are analyzed within the framework of the quantum theory of atoms in molecules (QTAIM). From the crossing points of the singlet (ground) and triplet (excited) potential energy curves, the barriers for dissociation (BFD) are estimated to be 25.2 kcal/mol (1.09 eV) for Zn , 22.8 kcal/mol (0.99 eV) for Cd , and 26.4 kcal/mol (1.14 eV) for Hg . For comparison and benchmarking purposes, the case of N is considered as a texbook example of metastability. At the equilibrium geometries, LDMs, which are used here as an electronic fingerprinting tool, discriminate and group together Group 12 M from its isoelectronic Group 11 M . While "classical" bonding indices are inconclusive in establishing regions of metastability in the bonding, it is shown that the one-electron Bohm quantum potential is promising in this regard.
研究了第12族双阳离子M²⁺（M = Zn、Cd、Hg）的电子结构和键合性质，并使用电子密度衍生量来表征这些物种的亚稳定性。特别令人感兴趣的是电子密度拉普拉斯算子∇²ρ(r)和单电子玻姆量子势（Q = -ħ²/2m ∇²ρ(r)/ρ(r)）沿键径提供的互补描述。此外，在分子中原子的量子理论（QTAIM）框架内分析了从对密度导出的性质，包括定域 - 离域矩阵（LDMs）和相互作用量子原子（IQA）能量。从单重态（基态）和三重态（激发态）势能曲线的交叉点估计，Zn²⁺的解离势垒（BFD）为25.2 kcal/mol（1.09 eV），Cd²⁺为22.8 kcal/mol（0.99 eV），Hg²⁺为26.4 kcal/mol（1.14 eV）。为了进行比较和基准测试，将N₂⁺的情况视为亚稳定性的教科书示例。在平衡几何构型下，此处用作电子指纹识别工具的LDMs将第12族M²⁺与其等电子的第11族M⁺区分开来并归为一组。虽然“经典”键合指数在确定键合中亚稳定性区域时没有定论，但结果表明单电子玻姆量子势在这方面很有前景。
