Kirian Richard A, Bean Richard J, Beyerlein Kenneth R, Yefanov Oleksandr M, White Thomas A, Barty Anton, Chapman Henry N
Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, Hamburg 22607, Germany
Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron, Notkestrasse 85, Hamburg 22607, Germany.
Philos Trans R Soc Lond B Biol Sci. 2014 Jul 17;369(1647):20130331. doi: 10.1098/rstb.2013.0331.
With the use of highly coherent femtosecond X-ray pulses from a free-electron laser, it is possible to record protein nanocrystal diffraction patterns with far more information than is present in conventional crystallographic diffraction data. It has been suggested that diffraction phases may be retrieved from such data via iterative algorithms, without the use of a priori information and without restrictions on resolution. Here, we investigate the extension of this approach to nanocrystals with edge terminations that produce partial unit cells, and hence cannot be described by a common repeating unit cell. In this situation, the phase problem described in previous work must be reformulated. We demonstrate an approximate solution to this phase problem for crystals with random edge terminations.
利用自由电子激光产生的高相干飞秒X射线脉冲，可以记录蛋白质纳米晶体的衍射图案，其包含的信息远比传统晶体学衍射数据丰富。有人提出，可以通过迭代算法从此类数据中检索衍射相位，而无需使用先验信息且不受分辨率限制。在此，我们研究将此方法扩展到具有边缘终止的纳米晶体，这些边缘终止会产生部分晶胞，因此无法用共同的重复晶胞来描述。在这种情况下，先前工作中描述的相位问题必须重新表述。我们展示了一种针对具有随机边缘终止的晶体的此相位问题的近似解决方案。
