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Updated: Jun 13, 2025

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解读原子极化性:访问的绝对半径和轨道贡献

Richa Khatiwada¹, Pengfei Li¹

¹Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States.

The journal of physical chemistry. A

|May 29, 2025

概括

在分子科学中至关重要的原子极化性受到内部轨道的影响,而不仅仅是最外围的轨道. 这挑战了极化性仅取决于原子体积和价值电子分布的观点.

科学领域:

量子化学是一个量子化学.
原子和分子物理原子和分子物理
计算化学计算化学

背景情况:

极化性是一个关键的原子和分子性质,它量化了电场下的电子云变形.
以前的模型将极化性等原子性质与最外的电子轨道分布和"绝对半径"联系起来.
计算原子性能的现有方法通常依赖于像斯莱特屏蔽常数这样的近似值.

研究的目的:

提出一个新的,准确的绝对原子半径的集合,从高层量子力学计算得出的.
通过使用基于绝对半径和最外围轨道半径分布函数的新方法来研究原子极化性.
通过评估内部轨道对原子极化能力的贡献,挑战传统的理解.

主要方法:

高级量子力学计算以确定新的绝对原子半径.
使用三个不同的方法计算原子极化率,包括球形电子分布和辐射分布函数.
计算的极化度与密度函数理论 (DFT) 的参考值进行比较.

主要成果:

新的绝对半径比以前的估计更准确.
计算的原子极化度提供了与DFT的定性,而不是定量一致.
内部轨道对原子极化有很大的贡献,与最外的轨道相比.
在CO2,CH4和SF6中,由于化学结合,分子极化性由最外围的轨道主导.

结论:

原子极化受原子体积和所有轨道的能量贡献的影响,而不仅仅是最外围的轨道.
内部轨道在原子极化性中的作用是显著的,并挑战了既定的范式.
分子中的化学结合限制了内部轨道的贡献,使分子偏振性与原子偏振性不同.

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