title: Multiwavelength anomalous diffraction at high x-ray intensity.
abstract: The multiwavelength anomalous diffraction (MAD) method is used to determine phase information in x-ray crystallography by employing anomalous scattering from heavy atoms. X-ray free-electron lasers (FELs) show promise for revealing the structure of single molecules or nanocrystals, but the phase problem remains largely unsolved. Because of the ultrabrightness of x-ray FEL, samples experience severe electronic radiation damage, especially to heavy atoms, which hinders direct implementation of MAD with x-ray FELs. Here, we propose a generalized version of MAD phasing at high x-ray intensity. We demonstrate the existence of a Karle-Hendrickson-type equation in the high-intensity regime and calculate relevant coefficients with detailed electronic damage dynamics of heavy atoms. The present method offers a potential for ab initio structural determination in femtosecond x-ray nanocrystallography.
authors.affiliation: Center for Free-Electron Laser Science, DESY, Hamburg, Germany. sangkil.son@cfel.de
authors.forename: Sang-Kil
authors.initials: SK
authors.lastname: Son
authors.forename: Henry N
authors.initials: HN
authors.lastname: Chapman
authors.forename: Robin
authors.initials: R
authors.lastname: Santra
mesh_terms: D017785:Photons; D013997:Time Factors; D014961:X-Ray Diffraction / Q000379:methods*