可转移的希什菲尔德原子模型用于快速评估无球原子形状因子
Michał Chodkiewicz1, Leonid Patrikeev1, Sylwia Pawlędzio1
1Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Żwirki i Wigury 101, Warszawa 02-089, Poland.
IUCrJ
|March 6, 2024
概括
结合希什菲尔德分区和多极扩张的新模型改善了X射线晶体学中原子参数的准确性. 这种方法提供了速度和精度之间的平衡,优于现有的可转移原子密度模型.
科学领域:
- 晶体学 晶体学是指结晶学.
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 无球原子电子密度模型在X射线晶体学中提高了原子参数的准确性.
- 目前的模型包括汉森-科潘斯 (快速) 和希尔什菲尔德原子精炼 (HAR) (准确但缓慢).
研究的目的:
- 为了测试一个混合模型,将希什菲尔德分区和多极扩张相结合,用于原子电子密度.
- 为了评估这一新型号的X射线晶体结构改进的准确性和速度.
主要方法:
- 开发了一个模型,使用预先计算的 Hirshfeld 分区电子密度存储在数据库中.
- 通过多极扩展 (l=7) 以数值辐射函数表示原子密度.
- 应用该模型来完善五个小分子结构,并计算crambin的形状因子.
主要成果:
- 混合模型的气参数比汉森-科潘斯数据库更准确.
- 精度略低于忽视环境的HAR,但包括环境影响在内,精度有所提高.
- 对于克兰宾 (0.73 Å 分辨率) 的计算速度很快 (12 个核心上的 68 秒).
结论:
- 混合模型为X射线精细化提供了精度和计算速度之间的有效平衡.
- 这种方法为确定精确的原子参数的现有方法提供了有价值的替代方案.
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