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

Molecular Orbital Theory I02:35

Molecular Orbital Theory I

31.7K
Overview of Molecular Orbital Theory
31.7K
Thermal Sigmatropic Reactions: Overview01:16

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...
2.1K
Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving01:29

Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving

40
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
40
Valence Bond Theory and Hybridized Orbitals02:38

Valence Bond Theory and Hybridized Orbitals

18.8K
According to valence bond theory, a covalent bond results when: (1) an orbital on one atom overlaps an orbital on a second atom, and (2) the single electrons in each orbital combine to form an electron pair. The strength of a covalent bond depends on the extent of overlap of the orbitals involved. Maximum overlap is possible when the orbitals overlap on a direct line between the two nuclei.
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
18.8K
MO Theory and Covalent Bonding02:40

MO Theory and Covalent Bonding

10.3K
The molecular orbital theory describes the distribution of electrons in molecules in a manner similar to the distribution of electrons in atomic orbitals. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital. Mathematically, the linear combination of atomic orbitals (LCAO) generates molecular orbitals. Combinations of in-phase atomic orbital wave functions result in regions with a high probability of electron density, while...
10.3K
Singularity Functions for Shear01:26

Singularity Functions for Shear

120
In structural analysis, singularity functions are crucial in simplifying the representation of shear forces in beams under discontinuous loading. These functions describe discontinuous  variations in shear force across a beam with varying loads by using a single mathematical expression, regardless of the complexity of the loading conditions. The singularity functions are derived from creating a free-body diagram of the beam and then making conceptual cuts at specific points to examine the...
120

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

Tuning Connectivity in Hybrid Organic-Inorganic Antimony Halides through Reactant Concentration Effects.

Inorganic chemistry·2026
Same author

A Benchmark and Basis-Set Extrapolation Study of Hyperfine Coupling Constants from the Random Phase Approximation and σ-Functionals.

The journal of physical chemistry. A·2026
Same author

A detailed comparison of ΔSCF methods with the constraint-based orbital-optimized excited state method.

Communications chemistry·2026
Same author

Formulation of an Efficient <math><mi>O</mi></math>(<i>M</i><sup>4</sup>)-Scaling Explicitly Correlated MP2-F12 Correction by Combining Numerical Quadrature with Density Fitting and CABS-RI.

Journal of chemical theory and computation·2026
Same author

Automated Discovery of Reactive Events via Hypergraph Mining of Ab Initio Atomistic Simulations.

Journal of chemical theory and computation·2026
Same author

Quantum chemistry - from the first steps to linear-scaling electronic structure methods.

Pure and applied chemistry. Chimie pure et appliquee·2025

相关实验视频

Updated: Jun 3, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.4K

基于近似交换内核的s-函数的自上而下的与自下而上的方法.

Yannick Lemke1, Christian Ochsenfeld1,2

  • 1Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, D-81377 Munich, Germany.

The journal of physical chemistry. A
|January 9, 2025
PubMed
概括

新的"自下而上"函数 (σ↑AXK) 通过解决自我相互作用和移位错误来改善密度函数理论计算,在关键基准上表现优于以前的方法.

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:

  • 基于亚亚巴特连接波动-散流定理 (ACFDT) 进行的 σ 和 τ 函数的研究.
  • 之前的研究采用了"自上而下"的 σ 函数的方法,在混合 PBE0 轨道上表现出良好的性能.
  • 大致交换内核 (AXK) 引入了非线性分线函数贡献.

研究的目的:

  • 为了检查分析"自下而上"的方法 σ-功能,在分析合强度集成之前插入spline函数.
  • 开发和评估新的自下而上的函数,标记为 σ↑AXK,以提高密度函数理论的准确性.

主要方法:

  • 采用了分析"自下而上"的方法,在ACFDT中整合了合强度积分之前的线条函数.
  • 对新的 σ↑AXK 函数,特别是 σ↑AXK@PBE0 的性能进行了评估,与现有的函数进行了对比.
  • 利用GMTKN55数据库,包括WTMAD-1和WTMAD-2指标,进行全面的基准测试.

主要成果:

  • 新的自下而上的 σ↑AXK 函数显著改善了"自上而下的"对应器,用于具有自我交互和移位错误的系统.
  • σ↑AXK@PBE0函数与常规 σ-函数,缩放 σ-函数,以及之前的 σ+SOSEX-和 τ-函数相比,表现优越.

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
Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
11:44

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes

Published on: November 12, 2016

17.8K

相关实验视频

Last Updated: Jun 3, 2025

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
08:04

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids

Published on: May 27, 2020

8.4K
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
Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes
11:44

Spin Saturation Transfer Difference NMR SSTD NMR: A New Tool to Obtain Kinetic Parameters of Chemical Exchange Processes

Published on: November 12, 2016

17.8K
  • 观察到非对应相互作用的精度略有降低,但GMTKN55数据库的整体性能得到了提高.

    • 结论:

    • 构建s-函数的"自下而上"方法提供了实质性的改进,特别是对于具有挑战性的电子结构问题.
    • σ↑AXK@PBE0代表了密度函数近似的显著进步,为各种化学系统提供了更准确的结果.
    • 这些发现为使用基于ACFDT的函数进行更可靠,更准确的计算化学预测铺平了道路.