对不寻常的SHELXL权重方案的补救措施
1Department of Chemistry, University of Kentucky, Lexington KY, 40506-0055 USA.
概括
这项研究提供了一种方法,通过调整SADABS中的数据减少设置来改进SHELXL中的权重参数. 这种方法有助于实现最佳的精细化参数,即使在具有挑战性的数据集.
科学领域:
- 晶体学 晶体学是指结晶学.
- 材料科学 材料科学 材料科学
- 计算化学计算化学
背景情况:
- 使用SHELXL进行标准的小分子结构改进,采用WGHT命令参数"a"和"b".
- 通常",a"<0.1和"b"<1是预期的,其中偏差表明数据质量差或模型缺陷等问题.
- 偶尔,尽管没有明显的模型问题,但大"b"值仍然存在,这表明数据不确定性被低估了.
研究的目的:
- 介绍一种在预期范围内获得SHELXL WGHT参数的实用方法.
- 为了解决结构改进中的持久大的"b"值.
- 探索数据减少参数对精炼权重的影响.
主要方法:
- 在布鲁克数据缩放,合并和吸收校正程序 (SADABS) 中微调参数.
- 调整数据减少设置以影响后续 SHELXL 改进中的权重方案.
- 方法的教学风格的介绍.
主要成果:
- 通过修改 SADABS 设置,在典型范围内的 WGHT 参数 ('a' < 0.1, 'b' < 1) 实现.
- 展示了一种简单的方法来解决持久的大b值.
- 为进一步调查SHELXL.L.中的权重计划提供了基础.
结论:
- 微调SADABS参数为优化SHELXL精炼权重提供了一个有效的策略.
- 这种方法可以帮助克服与低估数据不确定性相关的问题.
- 这些原则可能适用于其他数据缩小软件.
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