来自动力学理论和分子动力学模拟的HeHBr复合物的PES和运输特性
Fatemeh Aghababaei1, Ebrahim Nemati-Kande1
1Department of Physical Chemistry, Chemistry Faculty, Urmia University, Urmia, Iran. e.nemati@urmia.ac.ir.
Physical chemistry chemical physics : PCCP
|January 22, 2024
概括
这项研究计算了HeHBr范德瓦尔斯潜力和传输特性,如粘度和扩散系数. 结果显示了方法之间的一致性,Vashishta模型在模拟中提高了扩散精度.
科学领域:
- 物理化学 物理化学
- 计算化学的计算化学
- 原子和分子物理 原子和分子物理
背景情况:
- 准确的分子间潜力对于理解气体特性至关重要.
- 像HeHBr这样的范德瓦尔斯复合体作为理论计算的基准系统.
- 运输特性 (粘度,扩散) 是由分子间相互作用影响的关键宏观可观测值.
研究的目的:
- 计算HHBr范德瓦尔斯复合体的初始分子间潜在能量表面 (PES).
- 使用各种理论方法计算相互作用粘度 (η12) 和扩散 (D12) 系数.
- 评估不同潜在模型和模拟技术的准确性,以预测运输特性.
主要方法:
- 在CCSD (T) /a5zBF理论层面的Ab initio计算.
- 使用直角莱根德尔多项式的潜在能量表面扩张.
- 通过梅森-蒙奇克近似 (MMA),量子力学密切合 (CC) 和分子动力学 (MD) 模拟计算运输特性.
- 导出 LJ (12,6) 和 Vashishta MD 的力场.
- 计算能源依赖的Senftleben-Beenakker (SB) 截面及其温度依赖.
主要成果:
- 对HeHBr的ab initio PES的计算成功了.
- 运输物业的MMA计算显示与CC结果的良好一致,高达900K.
- 在MD模拟中,Vashishta三体潜能模型对扩散系数 (D12) 的精度高于LJ (12,6) 模型.
- 两种MD潜力模型都为粘度 (η12) 提供了结果,与CC方法相比,偏差不超过1%.
结论:
- 这项研究为HeHBr.Br提供了可靠的分子间潜力.
- 经典和量子方法提供了可比的传输系数,验证了理论方法.
- 像Vashishta这样的高级潜在模型对于精确的分子动力学模拟扩散是必不可少的.
相关概念视频
Arrhenius Plots
39.5K
The Arrhenius equation relates the activation energy and the rate constant, k, for chemical reactions. In the Arrhenius equation, k = Ae−Ea/RT, R is the ideal gas constant, which has a value of 8.314 J/mol·K, T is the temperature on the kelvin scale, Ea is the activation energy in J/mole, e is the constant 2.7183, and A is a constant called the frequency factor, which is related to the frequency of collisions and the orientation of the reacting molecules.
The Arrhenius equation can be used...
The Arrhenius equation can be used...
39.5K
The Born-Haber Cycle
21.9K
Lattice Energy
21.9K
The Bohr Model
53.9K
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as...
53.9K
Energy Diagrams, Transition States, and Intermediates
16.5K
Free-energy diagrams, or reaction coordinate diagrams, are graphs showing the energy changes that occur during a chemical reaction. The reaction coordinate represented on the horizontal axis shows how far the reaction has progressed structurally. Positions along the x-axis close to the reactants have structures resembling the reactants, while positions close to the products resemble the products. Peaks on the energy diagram represent stable structures with measurable lifetimes, while...
16.5K
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control
2.6K
The addition of a hydrogen halide to 1,3-butadiene gives a mixture of 1,2- and 1,4-adducts. Since more substituted alkenes are more stable, the 1,4-adduct is expected to be the major product. However, the product distribution is strongly influenced by temperature; low temperature favors the 1,2-adduct, whereas the 1,4-adduct is predominant at high temperature.
2.6K
The Quantum-Mechanical Model of an Atom
42.3K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
42.3K


