相关实验视频
Updated: Jul 14, 2026

10:37
Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
液态水中的核磁屏蔽和四极合电张器:一个联合的分子动力学模拟和量子化学研究
Teemu S Pennanen1, Juha Vaara, Perttu Lantto
1Contribution from NMR Research Group, Department of Physical Sciences, P.O. Box 3000, FIN-90014, University of Oulu, Finland. tepennan@paju.oulu.fi
Journal of the American Chemical Society
|September 2, 2004
概括
核磁共振 (NMR) 计算揭示了水分子从气体转化为液体的屏蔽和四极合的显著变化. 这些发现为水在不同状态的行为提供了新的见解.
科学领域:
- 计算化学计算化学
- 物理化学 物理化学
- 频谱学是一种光谱学.
背景情况:
- 核磁共振 (NMR) 光谱对于理解分子结构和动态至关重要.
- 水在液态和气态中的独特特性是许多科学学科的基础.
- 需要精确的理论计算来解释水的实验NMR数据.
研究的目的:
- 计算和比较NMR屏蔽和核四极合张量,用于气态和液态水.
- 研究相变对这些核性质的影响.
- 为水的实验研究提供理论基准.
主要方法:
- 利用哈特里-福克和密度函数理论 (DFT) 方法进行量子化学计算.
- 使用Car-Parrinello分子动力学 (MD) 来生成水配置的快照.
- 在两个状态中的400个样本中计算了平均同otropic和 anisotropic张量属性.
主要成果:
- 报告了氧-17 ((17) O) 和-1 ((1) H) 原子核的气体-液体化学转移.
- 量化了 (17) O和 ((2) H) 核的核四极合的变化.
- 呈现了两个状态的完全热平均屏蔽和四极合张量,包括液态水的新数据.
结论:
- 这项研究为液态水的热平均NMR张量提供了第一个全面的理论报告.
- 气态和液态水之间的NMR特性显著差异被观察并量化.
- 这些发现凸显了电子相关性和振荡平均值在准确描述水的行为方面的重要性.
相关概念视频
Van der Waals Interactions
Atoms and molecules interact with each other through intermolecular forces. These electrostatic forces arise from attractive or repulsive interactions between particles with permanent, partial, or temporary charges. The intermolecular forces between neutral atoms and molecules are ion–dipole, dipole–dipole, and dispersion forces, collectively known as van der Waals forces.Polar molecules have a partial positive charge on one end and a partial negative charge on the other end of the molecule,...
Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most...
The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...
Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
Electrostatic Boundary Conditions in Dielectrics
When an electric field passes from one homogeneous medium to another, crossing the boundary between the two mediums imparts a discontinuity in the electric field. This results in electrostatic boundary conditions that depend on the type of mediums the field propagates through.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.

