Jiang Linhua, Georgieva Dilyana, Zandbergen Henny W, Abrahams Jan Pieter
Department of Biophysical Structural Chemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
Acta Crystallogr D Biol Crystallogr. 2009 Jul;65(Pt 7):625-32. doi: 10.1107/S0907444909003163. Epub 2009 Jun 20.
Unit-cell determination is the first step towards the structure solution of an unknown crystal form. Standard procedures for unit-cell determination cannot cope with data collections that consist of single diffraction patterns of multiple crystals, each with an unknown orientation. However, for beam-sensitive nanocrystals these are often the only data that can be obtained. An algorithm for unit-cell determination that uses randomly oriented electron-diffraction patterns with unknown angular relationships is presented here. The algorithm determined the unit cells of mineral, pharmaceutical and protein nanocrystals in orthorhombic high- and low-symmetry space groups, allowing (well oriented) patterns to be indexed.
晶胞确定是解析未知晶体结构的第一步。标准的晶胞确定程序无法处理由多个晶体的单个衍射图案组成的数据收集，每个晶体的取向都是未知的。然而，对于对电子束敏感的纳米晶体来说，这些通常是唯一能获得的数据。本文提出了一种利用具有未知角度关系的随机取向电子衍射图案进行晶胞确定的算法。该算法确定了正交高对称和低对称空间群中矿物、药物和蛋白质纳米晶体的晶胞，从而能够对（取向良好的）图案进行指标化。
