相关实验视频

Updated: May 25, 2025

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry

Published on: April 8, 2020

基于神经网络的选择性配置交互方法对分子电子结构的选择性配置交互方法

Yorick L A Schmerwitz^1,2, Louis Thirion^1,3, Gianluca Levi¹

¹Science Institute and Faculty of Physical Sciences, University of Iceland, Reykjavík 107, Iceland.

Journal of chemical theory and computation

|February 27, 2025

概括

这项研究引入了一种新的计算方法,即选择性神经网络配置交互 (NNCI),用于准确的量子化学计算. NNCI显著减少了所需的决定因素的数量,使复杂的分子模拟更加有效.

科学领域:

量子化学是一个量子化学.
计算物理计算物理
材料科学材料科学材料科学

背景情况:

准确的量子化学计算对于理解分子性质至关重要.
传统的配置交互 (CI) 方法在大型系统的计算成本方面存在困难.
神经网络潜力为加速量子模拟提供了一个有希望的途径.

研究的目的:

开发和实施一种新的选择性神经网络配置交互 (NNCI) 方法.
评估NNCI对分子计算的性能.
为了证明NNCI在更大,更广泛的系统中的效率和适用性.

主要方法:

结合了Hartree-Fock与神经网络支持的量子集群解决器.
实现了选择性神经网络配置交互 (NNCI),具有灵活的基础集和边界条件.
对小分子的NNCI性能进行评估,将结果与完整的CI计算进行比较.

主要成果:

与全CI (10^10) 相比,NNCI准确地复制了N2的相关性能量,使用的决定因素显著减少 (4x10^5).
增加包含轨道的数量显示出明显的优势,而不是用更少的轨道接近完全的CI.
该方法证明了分子计算的高效率和可扩展性.

结论:

在电子结构计算方面,NNCI提供了一种计算效率高,准确的方法.
该方法在凝聚物质模拟软件中的实施扩大了CI计算的范围.
NNCI适用于更广泛的问题,包括通过嵌入扩展系统.

更多相关视频

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR

Published on: December 16, 2013

Spatial Separation of Molecular Conformers and Clusters

Spatial Separation of Molecular Conformers and Clusters

Published on: January 9, 2014

相关概念视频

Molecular Shapes

Molecular Shapes

Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.
Two regions of electron density in a diatomic...

π Electron Effects on Chemical Shift: Overview

π Electron Effects on Chemical Shift: Overview

An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...

VSEPR Theory

VSEPR Theory

Valence shell electron-pair repulsion theory (VSEPR theory) enables us to predict the molecular structure around a central atom from an examination of the number of bonds and lone electron pairs in its Lewis structure. The VSEPR model assumes that electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between these electron pairs by maximizing the distance between them. The electrons in the valence shell of a central atom form either bonding...

Molecular Orbital Theory I

Molecular Orbital Theory I

Overview of Molecular Orbital Theory

VSEPR Theory and the Basic Shapes

VSEPR Theory and the Basic Shapes

Overview of VSEPR Theory

Chemical Shift: Internal References and Solvent Effects

Chemical Shift: Internal References and Solvent Effects

In an NMR sample, precise measurement of the absolute absorption frequencies of nuclei is difficult. A standard internal reference compound is added, and the frequency difference between the reference signal and sample signals is measured.
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...