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晶体数据审稿意见-删除太多衍射点案例2 审稿意见原文： In six of those sevenstructures, significant amounts of data were excluded from the structuralrefinement through the use of OMIT instructions. Molecule 2c is the only onethat did not have omitted data. It is sometimes necessary to omit one or tworeflections that have been incorrectly measured, typically because they havebeen blocked by the diffractometer beamstop. Although not generallyrecommended, it can also be acceptable to use an OMIT instruction to limit theresolution of the data (i.e. OMIT 050) if the data quality drops at higher resolutions. It is NEVER acceptable,however, to omit several dozen to several hundred reflections, The structure of2d is the most egregious example. More than 400 reflections have been manuallyomitted from the refinement, leading to A and B-level checkCIF alerts. Theresponses of the authors to these alerts were that the data was incomplete dueto limited synchrotron time and that the reflections were in a skipped regionof the detector make no sense at al. The data absolutely were measured, andthey were measured on a laboratory diffractometer, not a synchrotron. If thosereflections are returned to the refinement, and the appropriate twin law isadded to the refinement (twin laws can be determined with free-for-academic-usesoftware like PLATON’s TWINROTMAT feature, or with tools built into thesoftware of the diffractometers used by the authors), the R1 dropsto less than 6%. The authors MUST re-refine all the structures (except 2c)without omitting dozens of reflections. 大意： 在这7个结构中的6个中，通过使用OMIT指令，大量数据被排除在结构精修之外。分子2c是唯一没有忽略数据的分子。有时有必要忽略一到两个被错误测量的衍射点，通常是因为它们被衍射仪的光束挡板遮挡了。虽然通常不推荐，但如果数据质量在更高分辨率下降低，也可以使用OMIT指令来限制数据的分辨率（即OMIT 0 50）。然而，忽略几十到几百个衍射点是绝对不可接受的，2d的结构是最令人震惊的例子。精修中手动忽略了400多个衍射点，导致A和B级checkCIF警报。作者对这些警报的回应是，由于同步加速器时间有限，数据不完整，衍射点在探测器的跳过区域根本没有意义。这些数据是绝对测量的，是在实验室衍射仪上测量的，而不是在同步加速器上测量的。如果将这些衍射点返回到精修中，并将适当的孪晶法则添加到精修中（孪晶法则可以用PLATON的TWINROTMAT功能等免费学术软件或作者使用的衍射仪软件中内置的工具来确定），R1将降至6%以下。作者必须在不忽略大量衍射点的情况下重新精修所有结构（2c除外）。 从审稿意见来看，2d只需要添加孪晶法则精修即可，不过作者是重新培养晶体测得了新的数据解决了该问题。 结构精修的过程中，如果需要忽略大量衍射点来降低R因子，或者即便忽略大量衍射点也无法降低R因子，那么很可能数据本身存在问题，如无序、孪晶、晶体质量差等，需要根据情况采取相应的举措。 视频讲解请参阅： 晶体数据审稿意见-删除太多衍射点案例2：https://www.bilibili.com/video/BV1qsxoeVEvz 声明：本文仅代表个人观点，笔者学识有限，资料整理过程中可能存在疏漏错误，请不吝指正。 如需PDF文档，请从以下链接下载： 通过网盘分享的文件：晶体数据审稿意见-删除太多衍射点案例2.pdf
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