Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Pressure and Volume in an Adiabatic Process01:27

Pressure and Volume in an Adiabatic Process

2.6K
Free expansion of a gas is an adiabatic process. However, there are few differences between free expansion and adiabatic expansion. During free expansion, no work is done, and there is no change in internal energy. But, for an adiabatic expansion, work is done, and there is a change in internal energy. During an adiabatic process, the relation between the pressure and volume is obtained from the condition for the adiabatic process, that is, 
2.6K
Adiabatic Processes for an Ideal Gas01:18

Adiabatic Processes for an Ideal Gas

3.0K
When an ideal gas is compressed adiabatically, that is, without adding heat, work is done on it, and its temperature increases. In an adiabatic expansion, the gas does work, and its temperature drops. Adiabatic compressions actually occur in the cylinders of a car, where the compressions of the gas-air mixture take place so quickly that there is no time for the mixture to exchange heat with its environment. Nevertheless, because work is done on the mixture during the compression, its...
3.0K
Diels–Alder vs Retro-Diels–Alder Reaction: Thermodynamic Factors01:31

Diels–Alder vs Retro-Diels–Alder Reaction: Thermodynamic Factors

4.8K
The Diels–Alder reaction is thermally reversible, meaning that the reaction reverts to the starting diene and dienophile under suitable temperatures. The forward reaction gives a cyclohexene derivative and is favored at low to medium temperatures. The reverse process, also called retro-Diels–Alder reaction, is a ring-opening process favored at high temperatures.
4.8K
Predicting Reaction Outcomes02:24

Predicting Reaction Outcomes

8.2K
Kinetics describes the rate and path by which a reaction occurs. In contrast, thermodynamics deals with state functions and describes the properties, behavior, and components of a system. It is not concerned with the path taken by the process and cannot address the rate at which a reaction occurs. Although it does provide information about what can happen during a reaction process, it does not describe the detailed steps of what appears on an atomic or a molecular level. On the other hand,...
8.2K
Reaction Mechanisms03:06

Reaction Mechanisms

25.4K
Chemical reactions often occur in a stepwise fashion, involving two or more distinct reactions taking place in a sequence. A balanced equation indicates the reacting species and the product species, but it reveals no details about how the reaction occurs at the molecular level. The reaction mechanism (or reaction path) provides details regarding the precise, step-by-step process by which a reaction occurs.
For instance, the decomposition of ozone appears to follow a mechanism with two steps:
25.4K
Temperature Dependence on Reaction Rate02:55

Temperature Dependence on Reaction Rate

81.1K
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
81.1K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Autobiography of Trygve Helgaker.

The journal of physical chemistry. A·2025
Same author

Correction: Molecular Aharonov-Bohm-type interferometers based on porphyrin nanorings.

Chemical science·2025
Same author

Interaction at pre-bonding distances and bond formation for open p-shell atoms with different orientations of their angular momenta.

The Journal of chemical physics·2025
Same author

Challenges and Advances in the Simulation of Targeted Covalent Inhibitors Using Quantum Computing.

The journal of physical chemistry letters·2025
Same author

Molecular Aharonov-Bohm-type interferometers based on porphyrin nanorings.

Chemical science·2025
Same author

Cluster perturbation theory. XI. Excitation-energy series using a variational excitation-energy function.

The Journal of chemical physics·2025

相关实验视频

Updated: Jun 4, 2025

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
10:52

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics

Published on: April 12, 2019

12.7K

在DFT中的经典反应障碍:一个阿迪亚巴特连接视角.

Andrew M Wibowo-Teale1, Bang C Huynh1, Trygve Helgaker2

  • 1School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, U.K.

Journal of chemical theory and computation
|December 23, 2024
PubMed
概括

这项研究引入了一种新的方法来可视化密度函数理论中的反应障碍. 它揭示了交换函数决定屏障精度和相关函数决定屏障形状,为改进计算化学模型提供了洞察力.

更多相关视频

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
12:11

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

8.1K
Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source
06:26

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

Published on: August 17, 2018

9.9K

相关实验视频

Last Updated: Jun 4, 2025

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
10:52

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics

Published on: April 12, 2019

12.7K
Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
12:11

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

8.1K
Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source
06:26

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

Published on: August 17, 2018

9.9K

科学领域:

  • 计算化学计算化学
  • 量子化学 是一个量子化学.
  • 密度函数理论密度函数理论

背景情况:

  • 经典反应障碍对于理解化学反应至关重要.
  • 密度函数理论 (DFT) 是用于计算这些障碍的广泛使用的方法.
  • DFT函数的错误可能导致预测反应障碍的不准确性.

研究的目的:

  • 引入一种新的"反应增离子-连接整合子"用于可视化反应障碍.
  • 分析DFT反应障碍中的功能驱动错误.
  • 分离和理解交换和相关函数对障碍高度的贡献.

主要方法:

  • 开发了基于密度固定的亚亚巴连接的"反应亚亚巴连接整数" ().
  • 在理论的合集群层面上使用Lieb最大化计算参考.
  • 通过对五种化学反应的合集群密度进行坐标缩放,从常见的交换相关函数中与近似的参考计算进行了比较.

主要成果:

  • 反应屏障高度直接可视化为图表下面的面积.
  • 的准确性仅取决于交换函数的准确性.
  • 的形状完全取决于相关函数,解释混合函数性能的变化.

结论:

  • 简单地增加混合函数的精确交换并不是改善反应障碍的可靠方法.
  • 准确的相关函数对于捕捉正确的形状和改善障碍预测至关重要.
  • 提出的数值数据可以指导开发更准确的相关函数.