通过"原型晶体结构"的能量差异将固态现象联系在一起
B Dittrich1, L E Connor1, F P A Fabbiani1
1Novartis Campus, Novartis Pharma AG, Postfach, Basel CH-4002, Switzerland.
IUCrJ
|April 17, 2024
概括
这项研究引入了原型晶体结构来分类分子固体,通过分析能量差异来解释混乱和多态性. 这一框架有助于理解复杂的晶体结构,并完善障碍建模.
科学领域:
- 固态化学和结晶学
- 材料科学是一种材料科学.
- 计算化学是一种计算化学.
背景情况:
- 分类是科学理解的基础.
- 现有的晶体结构模型难以完全解释无序,多态和固体解决方案.
- 晶体学中的障碍建模在解释障碍的发生和消失方面存在局限性.
研究的目的:
- 引入和扩展"原型晶体结构"的概念,以涵盖无序,多态,固体溶液,特殊位置和高Z结构.
- 为在晶体有机分子中出现混乱的发生提供能量解释.
- 在分析复杂的晶体结构和改进障碍建模时展示原型结构的应用.
主要方法:
- 基于量子化学能量差异的"原型晶体结构"概念的发展.
- 分析晶体结构,包括混乱和特殊位置,使用原型框架.
- 高Z'结构的能量分析,通过原型来理解它们的形成.
- 与现有的文献和实验性的最小平方精制实践进行比较.
主要成果:
- 原型晶体结构为理解混乱,多态和固体解决方案提供了一个统一的框架.
- 障碍组件之间的量子化学能量差异解释了障碍的存在和缺乏.
- 分析了雌二醇半水合物的晶体结构,说明了空间组/子组关系在解释与结合的原子乱中的作用.
- 高Z'结构在能量层面上被理解为源于在组合多种分子构造时,能量增益超过热能 (R·T).
结论:
- 原型晶体结构为固态分子结构提供了强大的分类工具.
- 能量方法为各种结构现象提供了强有力的解释,例如混乱和高Z'结构.
- 这一概念对改善实验晶体学中的障碍建模具有实际意义.
更多相关视频
07:48An Externally-Heated Diamond Anvil Cell for Synthesis and Single-Crystal Elasticity Determination of Ice-VII at High Pressure-Temperature Conditions
Published on: June 18, 2020
6.8K
07:24Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
17.1K
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
26.4K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.4K
02:22Structures of Solids
14.1K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
14.1K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.4K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
42.4K
02:54Molecular and Ionic Solids
17.1K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
17.1K
02:42Ionic Crystal Structures
14.3K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.3K
02:18X-ray Crystallography
23.9K
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
23.9K