Both nuclear and electronic dynamics contribute to protein function and need multiple and complementary techniques to reveal their ultrafast structural dynamics response. Real-space information obtained from the measurement of electron density dynamics by X-ray crystallography provides aspects of both, while the molecular physics of coherence parameters and frequency-frequency correlation needs spectroscopy methods. Ultrafast pump-probe applications of protein dynamics in crystals provide real-space information through direct X-ray crystallographic structure analysis or through structural optical crystallographic analysis. A discussion of methods of analysis using ultrafast macromolecular X-ray crystallography and ultrafast nonlinear structural optical crystallography is presented. The current and future high repetition rate capabilities provided by X-ray free electron lasers for ultrafast diffraction studies provide opportunities for optical control and optical selection of nuclear coherence which may develop to access higher frequency dynamics through improvements of sensitivity and time resolution to reveal coherence directly. Specific selection of electronic coherence requires optical probes, which can provide real-space structural information through photoselection of oriented samples and specifically in birefringent crystals. Ultrafast structural optical crystallography of photosynthetic energy transfer has been demonstrated, and the theory of two-dimensional structural optical crystallography has shown a method for accessing the structural selection of electronic coherence.

中文翻译：

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核和电子蛋白质动力学超快 X 射线晶体学和超快结构光学晶体学的进展和机遇。

核动力学和电子动力学都对蛋白质功能有贡献，并且需要多种互补的技术来揭示它们的超快结构动力学响应。通过 X 射线晶体学测量电子密度动力学获得的实空间信息提供了两者的各个方面，而相干参数和频频相关性的分子物理学则需要光谱方法。晶体中蛋白质动力学的超快泵浦探针应用通过直接 X 射线晶体结构分析或结构光学晶体分析提供真实空间信息。讨论了使用超快高分子X射线晶体学和超快非线性结构光学晶体学的分析方法。当前和未来 X 射线自由电子激光器为超快衍射研究提供的高重复率能力，为核相干性的光学控制和光学选择提供了机会，这可能会通过提高灵敏度和时间分辨率来直接揭示相干性，从而获得更高的频率动态。电子相干性的具体选择需要光学探针，它可以通过定向样品（特别是双折射晶体）的光选择来提供真实空间结构信息。光合能量转移的超快结构光学晶体学已经被证明，二维结构光学晶体学理论已经展示了一种实现电子相干性结构选择的方法。