Minimally resolution biased electron-density maps.
Minimally resolution biased electron-density maps.
复制标题
最小分辨率偏置电子密度图。
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. Rizzi
中科院分区：
文献类型：
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作者：
A. Altomare;C. Cuocci;C. Giacovazzo;Gihan Kamel;A. Moliterni;R. Rizzi
电子密度图计算傅立叶综合系数的基础上的结构因素。衍射实验提供的强度有限的分辨率，因此，傅立叶合成总是显示系列终止错误。分辨率越差，电子密度的傅立叶表示就越不精确。一般来说，每个原子峰从正确的位置偏移，显示出变形的（相对于原子域中电子的真实分布）轮廓，并且被一系列幅度逐渐减小的负和正波纹包围。描述了一种算法，该算法能够通过将峰重新定位在更正确的位置并通过修改峰轮廓以更好地拟合真实的原子电子密度来减小分辨率偏差。一些实验测试表明该程序的实用性。
Electron-density maps are calculated by Fourier syntheses with coefficients based on structure factors. Diffraction experiments provide intensities up to a limited resolution; as a consequence, the Fourier syntheses always show series-termination errors. The worse the resolution, the less accurate is the Fourier representation of the electron density. In general, each atomic peak is shifted from the correct position, shows a deformed (with respect to the true distribution of the electrons in the atomic domain) profile, and is surrounded by a series of negative and positive ripples of gradually decreasing amplitude. An algorithm is described which is able to reduce the resolution bias by relocating the peaks in more correct positions and by modifying the peak profile to better fit the real atomic electron densities. Some experimental tests are performed showing the usefulness of the procedure.