Hau-Riege Stefan P, Szoke Hanna, Chapman Henry N, Szoke Abraham, Marchesini Stefano, Noy Alexander, He Haifeng, Howells Malcolm, Weierstall Uwe, Spence John C H
Physics and Advance Technology, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94539, USA.
Acta Crystallogr A. 2004 Jul;60(Pt 4):294-305. doi: 10.1107/S0108767304010293. Epub 2004 Jun 24.
SPEDEN is a computer program that reconstructs the electron density of single particles from their X-ray diffraction patterns, using a single-particle adaptation of the holographic method in crystallography [Szöke, Szöke & Somoza (1997). Acta Cryst. A53, 291-313]. The method, like its parent, is unique because it does not rely on 'back' transformation from the diffraction pattern into real space and on interpolation within measured data. It is designed to deal successfully with sparse, irregular, incomplete and noisy data. It is also designed to use prior information for ensuring sensible results and for reliable convergence. This article describes the theoretical basis for the reconstruction algorithm, its implementation, and quantitative results of tests on synthetic and experimentally obtained data. The program could be used for determining the structures of radiation-tolerant samples and, eventually, of large biological molecular structures without the need for crystallization.
SPEDEN是一个计算机程序，它利用晶体学中全息方法的单粒子适配技术，从单粒子的X射线衍射图重建电子密度[绍克、绍克和索莫扎（1997年）。《晶体学报》A53卷，291 - 313页]。该方法与其母体方法一样独特，因为它不依赖于从衍射图到实空间的“逆”变换以及测量数据内的插值。它旨在成功处理稀疏、不规则、不完整和有噪声的数据。它还旨在利用先验信息来确保合理的结果和可靠的收敛。本文描述了重建算法的理论基础、其实现以及对合成数据和实验获得的数据进行测试的定量结果。该程序可用于确定耐辐射样品的结构，并最终用于确定大型生物分子结构，而无需结晶。
