为了准确的量子力学热化学: (1) 可扩展的实现和对债券附加性纠正和异体反应的比较
Haoyang Wu1, A Mark Payne1, Hao-Wei Pang1
1Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
The journal of physical chemistry. A
|May 16, 2024
概括
从量子力学计算中准确的形成度 (ΔHf) 从经验纠正中受益. 建议在同位体反应 (IDR) 上进行键附加性校正 (BAC),以提高准确性和稳定性.
科学领域:
- 计算化学的计算化学
- 热化学 热化学 热化学
- 量子力学就是量子力学.
背景情况:
- 精确的形成度 (ΔHf) 对于化学过程建模至关重要.
- 量子力学 (QM) 计算通常需要经验性纠正以匹配实验数据.
- 现有的方法包括原子化能量校正,键附加性校正 (BACs) 和同位体反应 (IDRs).
研究的目的:
- 实施和评估用于计算 ΔHf 的 BAC 和 IDR 使用 QM 结果.
- 为15个常见的模型化学得出和适应BAC.
- 为了比较BAC与IDR的准确性和稳定性.
主要方法:
- 使用开源软件Arkane进行计算.
- 从文献中收集了421种参考物种.
- 实施并安装了原子化能量校正和BAC (彼得森,安纳塔拉曼,梅利乌斯).
- 使用BAC和IDR进行比较,计算了ΔHf.
主要成果:
- 两种类型的BAC (彼得森,Anantharaman,Melius) 显示出类似的准确性.
- 安纳塔拉曼和梅利乌斯型BAC表现出更好的概括性.
- 对于常见的模型化学,BAC通常比IDR获得更高的准确性.
- 由于对参考物种和反应的敏感性,IDRs的强度较低.
结论:
- 推使用Anantharaman和Melius类型的BAC来准确测量QM衍生形成的度.
- 与IDR相比,BAC为热化学计算提供了更强大,更准确的方法.
相关概念视频
Thermodynamic Potentials
824
Thermodynamic potentials are state functions that are extremely useful in analyzing a thermodynamic system. They have dimensions of energy. The four important thermodynamic potentials are internal energy, enthalpy, Helmholtz free energy, and Gibbs free energy. These thermodynamic potentials can be expressed using two of the following variables: pressure, volume, temperature, and entropy. These two variables are expressed as the rate of change of the thermodynamic potential with respect to other...
824
Thermal Sigmatropic Reactions: Overview
2.1K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.1K
Thermodynamics: Chemical Potential and Activity
948
The effective concentration of a species in a solution can be expressed precisely in terms of its activity. Activity considers the effect of electrolytes present in the vicinity of the species of interest and depends on the ionic strength of the solution. The activity of a species is expressed as the product of molar concentration and the activity coefficient of the species.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
The thermodynamic equilibrium constant is more accurately defined in terms of activity rather than concentration.
948
Thermochemical Equations
28.6K
For a chemical reaction (the system) carried out at constant pressure – with the only work done caused by expansion or contraction – the enthalpy of reaction (also called the heat of reaction, ΔHrxn) is equal to the heat exchanged with the surroundings (qp).
28.6K
Maxwell's Thermodynamic Relations
2.7K
Maxwell's thermodynamic relations are very useful in solving problems in thermodynamics. Each of Maxwell's relations relates a partial differential between quantities that can be hard to measure experimentally to a partial differential between quantities that can be easily measured. These relations are a set of equations derivable from the symmetry of the second derivatives and the thermodynamic potentials.
All thermodynamic potentials are exact differentials. Therefore, their second-order...
All thermodynamic potentials are exact differentials. Therefore, their second-order...
2.7K
Thermodynamics: Activity Coefficient
1.4K
Activity is the measure of the effective concentration of the species in solution. It can be expressed as the product of the molar concentration of the species and its activity coefficient. The activity coefficient is a dimensionless quantity and depends on the total ionic strength of the solution.
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
The activity coefficient is a measure of the deviation from ideal behavior. When the ionic strength of the solution is minimal, the activity coefficient of an ionic species is close to unity, making...
1.4K


