对于含有的晶体系统,简单的"分子"校正可以在预测Cl电场梯度张量参数方面优于投影机增强波密度函数理论吗?
Cory M Widdifield1, Fatemeh Zakeri1
1Department of Chemistry and Biochemistry, University of Regina, Regina, Saskatchewan, Canada.
Magnetic resonance in chemistry : MRC
|November 11, 2023
概括
简单的分子校正 (SMC) 方法使35Cl电场梯度 (EFG) 张量参数的计算提高了30%. 包括旋转轨道效应进一步提高了无机系统的准确性,但不是有机系统.
科学领域:
- 计算化学的计算化学
- 固态化学 固态化学
- 量子化学 是一个量子化学.
背景情况:
- 多体膨胀 (MBE) 碎片方法准确计算晶体系统中的核磁共振 (NMR) 参数.
- 使用这些方法,已成功计算了14N和17O的电场梯度 (EFG) 张量参数.
- 简单的分子校正 (SMC) 方法通过孤立分子计算来调整NMR参数.
研究的目的:
- 评估SMC方法与PBE0混合交换相关性 (XC) 函数用于计算35Cl EFG张量参数的有效性.
- 评估在SMC框架内包括旋转轨道效应对35Cl EFG张量参数精度的影响.
- 为了将计算的35Cl EFG参数的准确性与基准投影机增强波 (PAW) DFT值进行比较.
主要方法:
- 简单分子校正 (SMC) 方法的应用,使用PBE0混合XC功能.
- 选择了8个有机和2个无机晶体结构,具有15个不同的位.
- 在特定系统的SMC计算中包括和评估旋转轨道效应.
主要成果:
- 使用PBE0的SMC方法提高了计算的35Cl四极合常量 (CQ) 和不对称性参数的准确性约30%.
- 对于重原子与结合的无机系统,将混合功能和旋转轨道效应结合在一起,进一步提高了准确性.
- 旋转轨道效应并没有提高有机系统中35Cl EFG张量参数的准确性.
结论:
- 该SMC方法,特别是与PBE0功能,在计算35ClEFG张量参数提供了显著的改进.
- 在含有重元素的无机晶体系统中,相对论旋转轨道效应对于准确的35Cl EFG计算至关重要.
- 对于35Cl EFG计算,SMC中旋转轨道效应的实用性是系统依赖的,在无机但不是有机化合物中显示出好处.
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