CAREER: Enabling the Accurate Simulation of Multi-Dimensional Core-Level Spectroscopies in Molecular Complexes using Time-Dependent Density Functional Theory

职业：使用瞬态密度泛函理论实现分子复合物中多维核心级光谱的精确模拟

• 批准号: 2337902
• 负责人: Daniel Nascimento
• 金额: $ 64.94万
• 依托单位: University of Memphis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-12-15 至 2028-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2337902&HistoricalAwards=false
• 关键词: CAREER; Enabling; Accurate; Simulation; Multi

With support from the Chemical Theory, Models and Computational Methods (CTMC) program in the Division of Chemistry, Dr. Daniel Nascimento of the University of Memphis is developing computational approaches to simulate how molecules interact with X-rays. These simulations provide valuable information on how molecules behave, and by extension, how they can be used and manipulated in technological applications relevant to medicine, materials science, engineering, and environmental chemistry. Dr. Nascimento and his research group will develop cost-effective algorithms to simulate multi-dimensional X-ray spectroscopies that will enable a better understanding of molecular systems relevant for the development of novel materials and technologies. These algorithms will be implemented as part of the Psi4 electronic structure package, an open-source, state-of-the-art quantum chemistry software package freely available to the chemistry community. As part of outreach and educational efforts, Dr. Nascimento will launch a summer program in computational chemistry targeting undergraduate students from across the Mid-South region. These efforts are designed to impact the recruitment and development of future theoretical and computational chemists and are seen as a vehicle to work toward building a diverse, talented future workforce for the field.Recent advancements in X-ray free-electron laser (XFEL) technologies have opened up new avenues for conducting multi-dimensional core-level spectroscopy experiments at high energies. However, to effectively interpret and make sense of the vast amount of data generated by these facilities, it is imperative to have precise theoretical models that can faithfully replicate the underlying processes. Current models employed in the interpretation of experimental X-ray data are either too simplified to be predictive or entail extensive computations that are practical only for relatively small molecules. Dr. Nascimento and his research group are taking a novel approach by harnessing the principles of response theory to develop, implement, and apply cost-effective algorithms for simulating multi-dimensional core-level spectroscopies in real-world systems, featuring around 100 to 150 atoms. These algorithms will be integrated into the Psi4 electronic structure package. Through this research effort, Dr. Nascimento aims to deepen our understanding of several critical aspects, including the significance of second-order relaxation effects in calculating excited-state transition moments in molecular complexes, the utilization of quasi-degenerate perturbation theory to introduce spin-orbit coupling effects into these transition moments, and the development of a state-specific strategy for addressing dissipation channels with minimal parameterization. The algorithms and computer programs resulting from this project are expected to enhance the ways in which multi-dimensional X-ray spectroscopy simulations are performed and to increase the reach and predictive ability of computational chemistry in the new era of XFEL-driven science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学系化学理论、模型和计算方法 (CTMC) 项目的支持下，孟菲斯大学的 Daniel Nascimento 博士正在开发计算方法来模拟分子如何与 X 射线相互作用。这些模拟提供了有关分子如何行为的宝贵信息，以及如何在与医学、材料科学、工程和环境化学相关的技术应用中使用和操纵它们。 Nascimento 博士和他的研究小组将开发具有成本效益的算法来模拟多维 X 射线光谱，从而更好地了解与新型材料和技术开发相关的分子系统。这些算法将作为 Psi4 电子结构包的一部分实现，Psi4 电子结构包是一个开源的、最先进的量子化学软件包，免费提供给化学界。作为推广和教育工作的一部分，纳西门托博士将针对中南地区的本科生推出计算化学夏季项目。这些努力旨在影响未来理论和计算化学家的招聘和发展，并被视为致力于为该领域打造多元化、有才华的未来劳动力的工具。X射线自由电子激光（XFEL）技术的最新进展为在高能下进行多维核心级光谱实验开辟了新途径。然而，为了有效地解释和理解这些设施生成的大量数据，必须拥有能够忠实复制底层过程的精确理论模型。当前用于解释实验 X 射线数据的模型要么过于简化而无法预测，要么需要进行大量计算，而这些计算仅适用于相对较小的分子。 Nascimento 博士和他的研究小组正在采用一种新颖的方法，利用响应理论的原理来开发、实施和应用具有成本效益的算法，用于模拟现实系统中的多维核心级光谱，该系统具有大约 100 到 150 个原子。这些算法将被集成到Psi4电子结构包中。通过这项研究工作，Nascimento 博士旨在加深我们对几个关键方面的理解，包括二阶弛豫效应在计算分子复合物激发态跃迁矩中的重要性，利用准简并微扰理论引入自旋-轨道耦合效应对这些过渡时刻的影响，以及开发一种特定于状态的策略，以最小的参数化来解决耗散通道。该项目产生的算法和计算机程序预计将增强多维 X 射线光谱模拟的执行方式，并提高 XFEL 驱动科学新时代计算化学的影响范围和预测能力。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。