Can we use on-the-fly quantum simulations to connect molecular structure and sunscreen action?
Can we use on-the-fly quantum simulations to connect molecular structure and sunscreen action?
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DOI：
10.1039/c8fd00228b
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发表时间：
2019-07
影响因子：
3.4
通讯作者：
Gareth W Richings;C. Robertson;S. Habershon
中科院分区：
文献类型：
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作者：
Gareth W Richings;C. Robertson;S. Habershon
新型分子防晒霜的彻底设计，具有改进的光稳定性、吸光度和光谱覆盖范围，是对基础化学科学的挑战。关联防晒霜分子结构和功能需要详细了解光激发后可用的松弛途径；然而，这些系统中复杂的耦合电子/核动力学对计算化学来说是一个严峻的挑战。为了应对这一挑战，我们最近开发了高效且准确的模拟方法来模拟一般分子系统的非绝热动力学，作为关联光致动力学和潜在防晒活性的途径。我们的方法将多配置时间相关 Hartree (MCTDH) 方法与使用机器学习生成的 PES 相结合，代表了一种用于精确波函数传播的新“即时”策略，并有可能提供一种新的“黑匣子”策略来询问一般光致能量传输过程中的超快动力学。在这里，我们展示了我们尝试应用这种方法来研究四种衍生自类菌孢素氨基酸（MAAs）的化合物的超快光化学，这些化合物被认为在藻类等微生物中充当微生物防晒剂。具体来说，我们研究了 MCTDH 中主动振动空间和非绝热电子态的选择如何强烈影响代表性 MAA 中超快动态弛豫的预测。我们的结果表明，使用 MCTDH 的“即时”量子动力学越来越可行，但与坐标选择和 diabatization 相关的重要障碍仍然存在。
The ground-up design of new molecular sunscreens, with improved photostability, absorbance and spectral coverage, stands as a challenge to fundamental chemical science. Correlating sunscreen molecular structure and function requires detailed insight into the relaxation pathways available following photoexcitation; however, the complex coupled electron/nuclear dynamics in these systems stands as a tough challenge to computational chemistry. To address this challenge, we have recently developed efficient and accurate simulation methods to model non-adiabatic dynamics of general molecular systems as a route to correlating photoinduced dynamics and potential sunscreen activity. Our approach, combining the multi-configuration time-dependent Hartree (MCTDH) method with PESs generated using machine-learning, represents a new "on-the-fly" strategy for accurate wavefunction propagation, with the potential to provide a new "black box" strategy for interrogating ultrafast dynamics in general photoinduced energy transport processes. Here, we illustrate our attempts to apply this methodology to study the ultrafast photochemistry of four compounds derived from mycosporine-like amino acids (MAAs), compounds which are believed to act as microbial sunscreens in micro-organisms such as algae. Specifically, we investigate how the choice of active vibrational space and diabatic electronic states in MCTDH strongly influences the predictions of ultrafast dynamic relaxation in representative MAAs. Our results serve to demonstrate that "on-the-fly" quantum dynamics using MCTDH is increasingly viable, but important barriers relating to coordinate choices and diabatisation remain.