Atomic pair distribution functions from textured polycrystalline samples: fundamentals [0.03%]
织构多晶样品的原子配对分布函数：基础理论
Zizhou Gong,Songsheng Tao,Simon J L Billinge
Zizhou Gong
Equations for the reduced structure function and atomic pair distribution function (PDF) of a textured polycrystalline sample are formulated in terms of the orientational distribution function (ODF) and the structure function from a single ...
The separation of the effects of atomic displacement and local resolution in crystallographic and cryo-electron microscopy maps [0.03%]
晶体学和Cryo-EM图中原子位移和局部分辨率影响的分离
Vladimir Y Lunin,Natalia L Lunina
Vladimir Y Lunin
Uncertainties in atomic coordinates and finite resolution blur the image of an atom's density present in the observed map. A resolution cutoff leads to an additional effect, known as Fourier ripples. Ignoring these ripples when calculating ...
X-ray dynamical diffraction wavefront division interferometer (double-slit diffraction) with an asymmetric monochromator [0.03%]
具有非对称单色器的X射线动态衍射波前分割干涉仪（双缝衍射）
Vahram Mkrtchyan,Minas Balyan,Sargis Petrosyan et al.
Vahram Mkrtchyan et al.
For incident spherical waves, a system consisting of an asymmetric monochromator and an X-ray interferometer with wavefront division is considered. The wave reflected from the monochromator, having passed through a double-slit system, falls...
Artificial intelligence in action: building simulation and analysis tools for powder diffraction [0.03%]
人工智能在行动：构建粉末衍射的模拟和分析工具
Paolo Scardi,Marcelo A Malagutti
Paolo Scardi
This paper explores the application of generative pre-trained transformer (GPT)-based large language models (LLMs) in the development of simulation and analysis tools for X-ray powder diffraction. We demonstrate how these models enable user...
Can Z, the number of formula units per unit cell, be a fraction? A report of the IUCr Commission on Crystallographic Nomenclature [0.03%]
Z值（单位晶胞中的公式单元数）可以是分数吗？——国际晶体学联合会命名委员会报告
Carolyn P Brock
Carolyn P Brock
The IUCr Commission on Crystallographic Nomenclature (the CCN) has considered the question of whether fractional values of Z, the number of formula units in the unit cell, can be permitted. The consideration was initiated by a crystallograp...
Modelling regularity of Si/Al distributions in disordered tectosilicates - application to zeolites with the GIS framework type [0.03%]
用GIS晶胞类型分子筛模型描述硅铝分布的周期性规律
Montauban Moreira de Oliveira Jr,Jean Guillaume Eon
Montauban Moreira de Oliveira Jr
As an extension of a previous work, we analyse ordered and disordered Si/Al distributions in a few tectosilicates. The method is based on an analysis of the inter-relations between maximal independent sets in a labelled quotient graph of th...
Updating direct methods IV. Reduction of the structural complexity when quartet invariant phases are estimated by using the Patterson map as prior information [0.03%]
直接法的修正Ⅳ。利用Patterson图作为先验信息估算四重码不变量相位简化结构复杂性
Carmelo Giacovazzo
Carmelo Giacovazzo
Quartet invariants play a minor role in modern direct methods. In practice, only the quartets whose cosine is estimated to be negative are used, as they have no correlation with the triplet invariants. However, their role remains marginal: ...
Machine learning for the classification of serial electron diffraction patterns: synthetic data [0.03%]
机器学习在串行电子衍射图谱分类中的应用：合成数据
Tatiana E Gorelik,Evgeny Gorelik
Tatiana E Gorelik
Serial electron crystallography faces a fundamental challenge due to the flat Ewald sphere resulting from the short electron wavelength, leading to limited 3D information in individual patterns. Recently, an algorithm for unit-cell determin...
3-Periodic weavings: piecewise linear embeddings of symmetric structures [0.03%]
3-周期性的编织：对称结构的分段线性嵌入
Michael O&#x;Keeffe,Michael M J Treacy
Michael O&#x;Keeffe
We provide a systematic account using symmetry and coordinates to explore symmetric (vertex- and edge-transitive) 3-periodic weavings of piecewise linear threads. The dia-w graph, derived from the diamond structure, generates an infinite fa...
B R Mobley,Kevin E Schmidt,R A Kirian
B R Mobley
Time-resolved small- and wide-angle X-ray scattering is a valuable tool for investigating biomolecular dynamics on a wide variety of timescales, without cryo-freezing or crystallization. However, some systems, such as the initial excitation...