限制DFT计算对氧化还原潜的准确性的因素
Bun Chan1,2
1Graduate School of Engineering, Nagasaki University, Nagasaki, Japan.
Journal of computational chemistry
|February 5, 2024
概括
计算化学方法通过平衡电离能和电子亲和度计算中的错误来准确预测氧化还原潜力,尽管溶解模型显示了局限性. 有机金属物种对准确的氧化还原潜力的预测提出了挑战.
科学领域:
- 计算化学计算化学
- 量子化学 是一个量子化学.
- 物理化学 物理化学
背景情况:
- 精确计算氧化还原潜力对于理解化学反应和设计新材料至关重要.
- 气相电离能 (IE) 和电子亲和力 (EA),以及溶解效应,是影响氧化还原电位精度的关键因素.
- 连续求解模型是常用的,但有已知的局限性.
研究的目的:
- 调查影响对氧化还原潜的计算化学计算准确性的因素.
- 评估各种计算方法的性能,以计算IE,EA和solvation效应.
- 在直接计算氧化还原潜力时分析错误传播和取消.
主要方法:
- 采用双混合密度函数理论 (DH-DFT) 方法以及IE和EA计算的低成本方法.
- 使用高级W3X-L基准进行比较.
- 评估连续溶解模型和直接计算的氧化还原潜力.
主要成果:
- DH-DFT方法 (例如,DSD-BLYP/ma-def2-QZVPP) 产生了IEs和EA在基准值的0.1 eV以内.
- 低成本方法的平均误差为~0.2-0.3 eV, ωB97X-3c是最准确的 (~0.15 eV).
- 连续性溶解模型的平均误差为~0.3 eV,直接计算的还原电位在各种方法中显示了类似的错误,归因于错误取消.
- 在有机金属物种中,由于气相IE和EA计算的不准确性,显著偏差 (>0.5 eV).
结论:
- 在IE,EA和溶解效应中,错误取消可以导致对某些系统的氧化还原潜力的预测具有惊人的准确性,特别是使用像GFN2-xTB这样的低成本方法.
- 连续求解模型在实现高精度方面存在重大局限性.
- 对有机金属物种的气相IE和EA的准确计算仍然是可靠的氧化还原潜力预测的主要挑战.
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