在溶解系统中激发状态动态的初始条件:一个案例研究.
Ethan R Curtis1,2, Chey M Jones1,2, Todd J Martínez1,2
1Department of Chemistry, Stanford University, Stanford, California 94305, United States.
确定量子力学/分子力学 (QM/MM) 模拟的"愈合时间"至关重要. 监测溶液温度提供了一个可靠的方法来设置这个愈合时间,确保准确的激发状态动态和光谱.
科学领域:
- 计算化学计算化学
- 分子动力学分子动力学
- 频谱学是一种光谱学.
背景情况:
- 模拟兴奋状态动态和计算凝聚相中的分子光谱,需要对初始条件进行准确的基态采样.
- 当前的方法通常在MM平衡后采用QM/MM博尔兹曼采样,需要"愈合时间"来适应QM/MM潜在能量表面.
- 之前的研究显示愈合时间的差异很大 (从femtosecond到picosecond),突出了对标准化指导方针的需求.
研究的目的:
- 研究愈合时间对非adiabatic动态和吸收光谱的影响.
- 建立可靠的指导方针,在QM/MM模拟中选择合适的愈合时间.
- 评估光谱性质对愈合时间的敏感性,与动态性质相比.
主要方法:
- 模拟的非adiabatic动态和计算的吸收光谱为一个捐赠者-接受者Stenhouse Adduct在.
- 在QM/MM轨迹开始时改变了愈合时间.
- 在愈合轨迹期间监测溶液温度作为潜在指标.
主要成果:
- 不够的愈合时间显著扭曲了基态产品的分支比率,并在非adiabatic动态中改变了放松路径.
- 愈合时间对吸收光谱的影响不那么明显,这表明光谱不是初始条件质量的敏感指标.
- 在愈合轨迹期间监测溶液温度,可以合理估计足够的愈合时间.
结论:
- 愈合时间是一个关键参数,必须仔细选择,以确保激发状态动态的QM/MM模拟的准确性.
- 吸收光谱不是可靠的指标来评估愈合时间的充分性.
- 在QM/MM轨迹的初始部分监测溶液温度是一种推的,用于确定愈合时间的实用方法.
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