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

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)01:20

Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)

1.1K
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
1.1K
Couples: Scalar and Vector Formulation01:21

Couples: Scalar and Vector Formulation

269
One might wonder how the captain of a large ship can navigate through the ocean with just a turn of the steering wheel. The answer lies in the concept of two parallel forces that are equal in magnitude and opposite sense, creating a couple moment.
A couple moment is a rotational force that tends to rotate the steering wheel. The wheel's rotation can either be in a clockwise or anticlockwise direction. The right-hand rule is a helpful method for determining the direction of a couple moment....
269
¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

1.8K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.8K
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)01:22

Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)

1.1K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the...
1.1K
Spin–Spin Coupling: One-Bond Coupling01:17

Spin–Spin Coupling: One-Bond Coupling

1.0K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.0K
Hybridization of Atomic Orbitals II03:35

Hybridization of Atomic Orbitals II

32.4K
sp3d and sp3d 2 Hybridization
32.4K

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

Analytic gradients and geometry optimization for orbital-optimized pair coupled cluster doubles.

The Journal of chemical physics·2026
Same author

A Flexible, Automated, and Basis-Set-Insensitive Domain-Based Charge-Transfer Decomposition for Correlated Wave Functions and Its Application to Inter- and Intramolecular Cases.

The journal of physical chemistry letters·2026
Same author

Ionization Potentials at Mean-Field Computational Cost: The Extended Koopmans' Framework for pCCD.

Journal of chemical theory and computation·2026
Same author

Tuning Domain-Based Charge Transfer in Organic Dyes: Impact of Heteroatom Doping on the π-Linker of Carbazole-Based Systems.

The journal of physical chemistry. A·2025
Same author

Electron Affinities from Equation-of-Motion Frozen Pair-Type Coupled Cluster Methods and Their Dependence on Single Excitations, Molecular Orbitals, and Basis Set Sizes.

Journal of chemical theory and computation·2025
Same author

Expectation Value-pCCD-Based Methods for Single-Electron Properties.

The journal of physical chemistry. A·2025
Same journal

Grammatical evolution-based design of nucleotic analogs for SARS-CoV-2's replication-transcription complex.

Physical chemistry chemical physics : PCCP·2026
Same journal

Optical frequency comb Fourier transform spectroscopy of the CH<sub>2</sub><sup>79</sup>Br<sup>81</sup>Br, CH<sub>2</sub><sup>79</sup>Br<sub>2</sub>, and CH<sub>2</sub><sup>81</sup>Br<sub>2</sub> isotopologues in the 1180-1210 cm<sup>-1</sup> region.

Physical chemistry chemical physics : PCCP·2026
Same journal

First-principles modeling of polysilazane-derived SiCNH ceramics: insights into the organization of the free-carbon phase.

Physical chemistry chemical physics : PCCP·2026
Same journal

Determining the binding strength of phenolic anchoring groups on hydrated WO<sub>3</sub> surfaces.

Physical chemistry chemical physics : PCCP·2026
Same journal

Activation of methane by the tantalum trioxide anion, TaO<sub>3</sub><sup></sup>.

Physical chemistry chemical physics : PCCP·2026
Same journal

Temperature-dependent recombination dynamics in BH/ZnBr<sub>2</sub> Co-doped CsPbI<sub>3</sub> thin films.

Physical chemistry chemical physics : PCCP·2026
查看所有相关文章

相关实验视频

Updated: Jul 16, 2025

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

8.2K

基于对合集群双重方法的静态嵌入.

Rahul Chakraborty1, Katharina Boguslawski1, Paweł Tecmer1

  • 1Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Toruń, Poland. ptecmer@fizyka.umk.pl.

Physical chemistry chemical physics : PCCP
|September 14, 2023
PubMed
概括
此摘要是机器生成的。

本研究引入了一种新的量子嵌入方法,将波函数理论与密度函数理论 (WTF-in-DFT) 结合在密度函数理论 (WTF-in-DFT) 中,并配对集群倍数 (pCCD) 和配对集群校正. 这种方法在大型分子系统中准确地模拟了激发状态.

更多相关视频

Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.0K
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.3K

相关实验视频

Last Updated: Jul 16, 2025

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

8.2K
Spatial Separation of Molecular Conformers and Clusters
10:37

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

9.0K
Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
05:51

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method

Published on: July 19, 2019

6.3K

科学领域:

  • 量子化学是一种量子化学.
  • 计算化学是一种计算化学.
  • 理论化学是一种理论化学.

背景情况:

  • 量子嵌入方法对于建模大型分子系统至关重要.
  • 偶联集群双重 (pCCD) 擅长在有效地描述强烈相关的系统.
  • 动态关联效应需要扩展到基本的pCCD之外.

研究的目的:

  • 在密度函数理论 (WTF-in-DFT) 嵌入方案中开发一种新的波函数理论.
  • 为了实现动态相关性,将线性化的合集群校正 (LCCSD) 纳入.
  • 应用该方法来计算各种分子系统的垂直激发能.

主要方法:

  • 使用pCCD开发一个WTF-in-DFT嵌入方案.
  • 线性合集群单双 (LCCSD) 的应用,用于地面和激发状态.
  • 使用运动方程 (EOM) 形式主义进行激发状态计算.
  • 对水-氨复合物,微溶提胺和四甲化物进行测试.

主要成果:

  • 通过EOM-pCCD-LCCSD-in-DFT方法,可以准确计算垂直激发能.
  • 该方法成功地模拟了从碎片到超分子结构的激发能量的变化.
  • 轨道纠和相关性分析验证了嵌入潜力的质量.

结论:

  • 拟议的EOM-pCCD-LCCSD-in-DFT方法是大型分子激发状态计算的一个有前途的计算工具.
  • 这种混合量子嵌入方案有效地平衡了准确性和计算成本.
  • 该方法提供了对复杂化学系统电子激发状态的可靠见解.