系统 DFT 建模范德瓦尔斯异构结构从完整的配置基础应用到 γ-PC/WS2
1Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, FIN-90014 Oulu, Finland.
Journal of chemical theory and computation
|March 6, 2024
概括
范德瓦尔斯异构结构的密度函数理论 (DFT) 建模可以锁定在局部最小值中. 本研究介绍了一种探索所有超级细胞配置的方法,揭示了DFT结果的影响.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 范德瓦尔斯异构结构的密度函数理论 (DFT) 建模可以被周期性边界条件所限制,从而导致在元稳定配置中人工锁定.
- 超级电池的构造显著影响了几何优化,可能会在有限的应变空间内捕获局部能量最小值的计算.
研究的目的:
- 从两个单层单元细胞中全面生成所有可能的双层超级细胞组合的算法.
- 调查超细胞结构对范德瓦尔斯异构结构的DFT建模结果的影响.
- 分析各种紧张配置的几何,能量和电子特性.
主要方法:
- 开发了一种算法,系统地生成两个单层单元细胞的所有超级细胞组合.
- 应用了该算法,为γ-PC/WS2创建了18123个双层超级细胞,包括各种菌株类型 (同otropic,异otropic,内层剪切).
- 在45个选择的同位素应变配置上进行了DFT计算,以分析它们的特性.
主要成果:
- 这项研究产生了一套18123个双层超级细胞的综合集,用于g-PC/WS.
- 分析揭示了不同菌株类型和超细胞结构对DFT结果的影响.
- DFT优化显示了不同变种和扭曲角度的几何,能量和带结构特征的变化.
结论:
- 超级细胞构造对范德瓦尔斯异构结构建模的DFT结果产生了重大影响.
- 对各种超级细胞配置进行深入的选对于准确的表征至关重要.
- 证明的方法为未来的范德瓦尔斯异构结构和相关材料的表征提供了一个强大的方法.
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
26.5K
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...
26.5K
02:18Network Covalent Solids
13.5K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
13.5K
02:38Valence Bond Theory and Hybridized Orbitals
19.3K
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...
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...
19.3K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.5K
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,...
42.5K
03:24Hybridization of Atomic Orbitals I
47.1K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
47.1K
02:37Metallic Solids
18.4K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.4K