Zadeh Dariush H
Erie Community College (ECC), State University of New York (SUNY), 6205 Main Street, Williamsville, NY, 14221, USA.
J Mol Model. 2017 Nov 28;23(12):357. doi: 10.1007/s00894-017-3534-2.
The electronic structures of elements in the periodic table were analyzed using available experimental ionization energies. Two new parameters were defined to carry out the study. The first parameter-apparent nuclear charge (ANC)-quantified the overall charge of the nucleus and inner electrons observed by an outer electron during the ionization process. This parameter was utilized to define a second parameter, which presented the shielding ability of an electron against the nuclear charge. This second parameter-electron shielding effect (ESE)-provided an insight into the electronic structure of atoms. This article avoids any sort of approximation, interpolation or extrapolation. First experimental ionization energies were used to obtain the two aforementioned parameters. The second parameter (ESE) was then graphed against the electron number of each element, and was used to read the corresponding electronic structure. The ESE showed spikes/peaks at the end of each electronic shell, providing insight into when an electronic shell closes and a new one starts. The electronic structures of elements in the periodic table were mapped using this methodology. These graphs did not show complete agreement with the previously known "Aufbau" filling rule. A new filling rule was suggested based on the present observations. Finally, a new way to organize elements in the periodic table is suggested. Two earlier topics of effective nuclear charge, and shielding factor were also briefly discussed and compared numerically to demonstrate the capability of the new approach.
利用现有的实验电离能分析了元素周期表中元素的电子结构。定义了两个新参数来进行这项研究。第一个参数——表观核电荷(ANC)——量化了外层电子在电离过程中观察到的原子核和内层电子的总电荷。利用这个参数定义了第二个参数,该参数表示电子对核电荷的屏蔽能力。第二个参数——电子屏蔽效应(ESE)——为了解原子的电子结构提供了一个视角。本文避免了任何形式的近似、插值或外推。首先使用实验电离能来获得上述两个参数。然后将第二个参数(ESE)与每个元素的电子数作图,并用于解读相应的电子结构。ESE在每个电子壳层的末端显示出尖峰/峰值,这为了解电子壳层何时闭合以及新壳层何时开始提供了线索。使用这种方法绘制了元素周期表中元素的电子结构。这些图表与先前已知的“构造原理”填充规则并不完全一致。基于目前的观察结果提出了一种新的填充规则。最后,提出了一种在元素周期表中排列元素的新方法。还简要讨论了有效核电荷和屏蔽因子这两个早期主题,并进行了数值比较,以展示新方法的能力。