Experimental and theoretical studies into molecular photodynamics on the ultrafast dynamics

超快动力学分子光动力学的实验和理论研究

• 批准号: 2890140
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2890140
• 关键词: Experimental; theoretical; studies; into; molecular

Over the last few decades, developments in sub-picosecond laser technologies, especially at free-electron laser (FEL) facilities, have allowed for an increasingly accessible means of exploring the ultrafast photo-initiated dynamics of various small molecules in the gas-phase. In particular, utilising ultrafast lasers in pump-probe experiments has led to the concept of a "molecular movie", which encompasses following molecular dynamics on timescales as short as a few femtoseconds. Through developing comprehensive quantum molecular structure and trajectory theories for such experiments, experimental outcomes of such dynamical experiments are sought to be rationalised. However, the time taken to perform quantum chemical calculations at a desired level of accuracy often scales exponentially with the size and number of degrees of freedom in a chemical system. Hence, developing algorithms which maximise the accuracy of quantum chemical calculations yet which correspondingly minimise the run-time remains an important research theme in theoretical chemistry. Further to this, there often remains the need to synthesise the results of theoretical calculations with experimentally determined parameters for a given experiment so as to allow for a direct comparison between theory and experiment. The aim of this project is to develop and implement existing quantum chemical methods in order to study the ultrafast molecular dynamics of select small chemical systems. Another main focus will be developing a means of using theory and a knowledge of experimental setup to predict experimental parameters which can be measured at experiments to be conducted on such molecules at ultrafast laser facilities. Specifically, integrating theory with the outcomes of a set of experiments called Coulomb explosion imaging (CEI) experiments will be a focus of this work; this is something which has not yet been achieved at a considerable depth of theory. CEI experiments involve the rapid fragmentation of a highly-charged precursor ion; fragments are then detected spatially and temporally according to their mass-to-charge ratios by two-dimensional detector, where the radius of an ion detected within a given time-interval on the detector is indicative of its velocity within the detector plane. This project will also involve taking part in running and acquiring data from CEI experiments at facilities such as the Artemis laser facility in Oxfordshire. This project falls within the EPSRC Physical Sciences Research area.

在过去的几十年里，亚皮秒激光技术的发展，特别是在自由电子激光（FEL）设施，已经允许越来越容易获得的手段来探索各种小分子在气相中的超快光引发动力学。特别是，利用超快激光泵浦探测实验导致了“分子电影”的概念，其中包括以下分子动力学的时间尺度短到几个飞秒。通过发展全面的量子分子结构和轨道理论，这样的动力学实验的实验结果是合理的。然而，以期望的精度水平执行量子化学计算所花费的时间通常与化学系统中自由度的大小和数量成指数级。因此，开发最大限度地提高量子化学计算精度但相应地最小化运行时间的算法仍然是理论化学中的一个重要研究主题。除此之外，通常仍然需要将理论计算的结果与给定实验的实验确定的参数进行综合，以便允许理论与实验之间的直接比较。该项目的目的是发展和实施现有的量子化学方法，以研究选定的小化学系统的超快分子动力学。另一个主要重点将是开发一种方法，利用理论和实验设置的知识来预测实验参数，这些参数可以在超快激光设施中对这些分子进行实验时测量。具体来说，将理论与一组称为库仑爆炸成像（CEI）实验的结果相结合将是这项工作的重点;这是尚未在相当深入的理论中实现的。CEI实验涉及高电荷前体离子的快速碎裂;然后通过二维检测器根据其质荷比在空间和时间上检测碎片，其中在检测器上的给定时间间隔内检测到的离子的半径指示其在检测器平面内的速度。该项目还将涉及参与运行和获取CEI在牛津郡Artemis激光设施等设施的实验数据。该项目属于EPSRC物理科学研究领域的福尔斯。