Imaging atom clusters by hard X-ray free-electron lasers

The ingenious idea of single-molecule imaging by hard X-ray Free Electron Laser (X-FEL) pulses was recently proposed by Neutze et al. (Nature, 406 (2000) 752). However, in their numerical modelling of the Coulomb explosion, several interactions were neglected and no reconstruction of the atomic structure was given. In this work we carried out improved molecular-dynamics calculations including all quantum processes which affect the explosion. Based on this time evolution, we generated composite elastic-scattering patterns, and by using Fienup's algorithm successfully reconstructed the original atomic structure. The critical evaluation of these results gives guidelines and sets important conditions for future experiments aiming at single-molecule structure solution.