Bortel Gábor, Tegze Miklós
Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences, 1525 Budapest, PO Box 49, Hungary.
Acta Crystallogr A. 2011 Nov;67(Pt 6):533-43. doi: 10.1107/S0108767311036269. Epub 2011 Oct 13.
Very short pulses of X-ray free-electron lasers opened the way to obtaining diffraction signal from single particles beyond the radiation dose limit. For three-dimensional structure reconstruction many patterns are recorded in the object's unknown orientation. A method is described for the orientation of continuous diffraction patterns of non-periodic objects, utilizing intensity correlations in the curved intersections of the corresponding Ewald spheres, and hence named the common arc orientation method. The present implementation of the algorithm optionally takes into account Friedel's law, handles missing data and is capable of determining the point group of symmetric objects. Its performance is demonstrated on simulated diffraction data sets and verification of the results indicates a high orientation accuracy even at low signal levels. The common arc method fills a gap in the wide palette of orientation methods.
极短脉冲的X射线自由电子激光为在超过辐射剂量极限的情况下从单个粒子获取衍射信号开辟了道路。对于三维结构重建，许多图案是在物体未知取向的情况下记录的。本文描述了一种用于确定非周期性物体连续衍射图案取向的方法，该方法利用相应埃瓦尔德球弯曲交点处的强度相关性，因此被称为公共弧取向法。该算法的当前实现可选择考虑弗里德尔定律，处理缺失数据，并能够确定对称物体的点群。在模拟衍射数据集上展示了其性能，结果验证表明即使在低信号水平下也具有很高的取向精度。公共弧法填补了众多取向方法中的一个空白。
