title: SPEDEN: reconstructing single particles from their diffraction patterns.
abstract: 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.
authors.affiliation: Physics and Advance Technology, Lawrence Livermore National Laboratory, PO Box 808, Livermore, CA 94539, USA. hauriege1@llnl.gov
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Hau-Riege
authors.forename: Hanna
authors.initials: H
authors.lastname: Szoke
authors.forename: Henry N
authors.initials: HN
authors.lastname: Chapman
authors.forename: Abraham
authors.initials: A
authors.lastname: Szoke
authors.forename: Stefano
authors.initials: S
authors.lastname: Marchesini
authors.forename: Alexander
authors.initials: A
authors.lastname: Noy
authors.forename: Haifeng
authors.initials: H
authors.lastname: He
authors.forename: Malcolm
authors.initials: M
authors.lastname: Howells
authors.forename: Uwe
authors.initials: U
authors.lastname: Weierstall
authors.forename: John C H
authors.initials: JC
authors.lastname: Spence
mesh_terms: D000465:Algorithms; D004583:Electrons; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008433:Mathematics; D012984:Software; D014961:X-Ray Diffraction / Q000379:methods*