探索离子极化性及其与范德瓦尔斯辐射的相关性:理论研究
Madelyn Smith1, Richa Khatiwada1, Pengfei Li1
1Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States.
Journal of chemical theory and computation
|September 28, 2024
概括
这项研究使用量子力学系统地推导出原子和离子的极化性,发现了极化性和原子和子的范德瓦尔斯半径之间的关系. 开发的12-6-4模型准确地预测了相互作用能量,推进了极化力场.
科学领域:
- 计算化学的计算化学
- 量子力学就是量子力学.
- 物理化学 物理化学
背景情况:
- 精确的极化性 (α) 对于分子模拟至关重要,它会影响诸如分子相互作用和介电常数之类的特性.
- 为离子开发可极化力场 (FFs) 是一个挑战,缺乏全面的极化数据.
- 极化度量化了电场下的电子云扭曲,这是一个基本的原子和分子性质.
研究的目的:
- 通过高层次量子力学计算,系统地推导出一套全面的原子和离子极化性.
- 调查衍生极化度与先前确定的范德瓦尔斯 (VDW) 半径之间的关系.
- 开发和验证12-6-4模型的参数化策略,以改进离子相互作用建模.
主要方法:
- 高级量子力学计算来推导原子和离子的极化性.
- 分析极化度 (α) 和范德瓦尔斯 (VDW) 半径 (RVDW) 之间的关系,特别是RVDW α1/7和RVDW α1/3.
- 用于确定分散系数的不同方法的比较 (伦敦方程,斯莱特-柯克伍德方程,SAPT,TD-DFT).
- 使用SAPT和SobEDA对12-6-4模型的参数化和验证,用于涉及离子和各种连接体的相互作用.
主要成果:
- 导出了一套系统的原子和离子极化性,与实验数据有很好的一致性.
- 发现关系RVDW α1/7在原子和离子上占主导地位,但在离子上却没有.
- 不同的分散系数方法显示,尽管有偏差的大小,但相关性很高,这表明在缩放后的适用性.
- 具有新参数化的12-6-4模型有效地重现了总和单个相互作用能量组件.
结论:
- 衍生的极化性为分子模拟和可极化力场的开发提供了宝贵的资源.
- 阴离子在RVDW-α关系中的独特行为突出了它们电子云相互作用的复杂性.
- 经过验证的12-6-4模型和参数化策略为模拟离子-连接体相互作用提供了强大的方法.
- 这项工作为推进下一代离子模型和计算化学中极化力场的发展做出了重大贡献.
相关概念视频
Van der Waals Interactions
63.6K
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.
63.6K
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
34.5K
Thus far, the ideal gas law, PV = nRT, has been applied to a variety of different types of problems, ranging from reaction stoichiometry and empirical and molecular formula problems to determining the density and molar mass of a gas. However, the behavior of a gas is often non-ideal, meaning that the observed relationships between its pressure, volume, and temperature are not accurately described by the gas laws.
34.5K
Ionic Radii
27.5K
Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...
27.5K
Van der Waals Equation
4.0K
The ideal gas law is an approximation that works well at high temperatures and low pressures. The van der Waals equation of state (named after the Dutch physicist Johannes van der Waals, 1837−1923) improves it by considering two factors.
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...
4.0K
Bond Polarity, Dipole Moment, and Percent Ionic Character
28.6K
Bond Polarity
28.6K
Potential Due to a Polarized Object
370
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
370


