Kozlov Alexander, Gureyev Timur E, Paganin David M, Martin Andrew V, Caleman Carl, Quiney Harry M
ARC Centre of Excellence in Advanced Molecular Imaging, School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
Faculty of Health Sciences, University of Sydney, Sydney, NSW 2006, Australia.
IUCrJ. 2020 Oct 20;7(Pt 6):1114-1123. doi: 10.1107/S2052252520013019. eCollection 2020 Nov 1.
Resolving the electronic structure of single biological molecules in their native state was among the primary motivations behind X-ray free-electron lasers. The ultra-short pulses they produce can outrun the atomic motion induced by radiation damage, but the electronic structure of the sample is still significantly modified from its original state. This paper explores the decoherence of the scattered signal induced by temporal evolution of the electronic structure in the sample molecule. It is shown that the undamaged electron density of a single-molecule sample can often be retrieved using only the two most occupied modes from the coherent mode decomposition of the partially coherent diffraction fluence.
解析处于天然状态的单个生物分子的电子结构是X射线自由电子激光背后的主要动机之一。它们产生的超短脉冲可以超越由辐射损伤引起的原子运动，但样品的电子结构仍会与原始状态有显著差异。本文探讨了样品分子中电子结构的时间演化所引起的散射信号的退相干。结果表明，通常仅使用部分相干衍射通量的相干模式分解中的两个占据最多的模式，就可以恢复单分子样品的未受损电子密度。
