title: Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity.
abstract: We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit, we employ a Monte-Carlo-molecular dynamics-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units, we simulate the diffraction pattern of a crystal larger than the transverse x-ray beam profile, a situation commonly encountered in femtosecond nanocrystallography experiments with focused x-ray free-electron laser radiation. Radiation damage is not spatially uniform and depends on the fluence associated with each specific region inside the crystal. To investigate the effects of uniform and non-uniform fluence distribution, we have used two different spatial beam profiles, Gaussian and flattop.
authors.forename: Malik Muhammad
authors.initials: MM
authors.lastname: Abdullah
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Jurek
authors.forename: Sang-Kil
authors.initials: SK
authors.lastname: Son
authors.forename: Robin
authors.initials: R
authors.lastname: Santra