Quantum chemical methods for studying photon and electron driven processes

研究光子和电子驱动过程的量子化学方法

• 批准号: 1800171
• 负责人: Spiridoula Matsika
• 金额: $ 45万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1800171&HistoricalAwards=false
• 关键词: Quantum; chemical; methods; studying; photon

Professor Spiridoula Matsika of Temple University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry Division to develop and apply theoretical methods to better understand electron-driven processes. Heat, light (photons), and electrons provide different routes to initiate chemical reactions. While heat- and photon-driven chemical processes are well studied, electron-driven processes are not well understood, even though electrons are ubiquitous in nature. Electrons are generated by radiation, and their collisions with atoms and molecules are essential in biology and chemistry, as well as in technology. Examples of electron-driven phenomena can be found in interstellar chemistry, radiation chemistry, environmental chemistry, stability of waste repositories, plasma processing of materials for microelectronic devices, and other applications. A major complication in electron-driven processes is that the states that are involved are metastable. Matsika and her research group develop computational and theoretical approaches to treat metastable states and their chemical reactivity. They specifically apply these methods to better understand DNA damage by radiation as well as formation of prebiotic molecules in interstellar medium. The research is expected to provide valuable insights into the understanding of important electron-driven phenomena in many areas of chemistry, specifically biological systems and formation of prebiotic molecules. This research is carried out by a research team involving collaboration of undergraduate and graduate students with postdoctoral associates. The involvement of high school students in research activities inspires students to be involved in science. This involvement has a very positive effect in their education and future career prospects.Conventional quantum chemical methods cannot be applied to study metastable states (or resonances), and several approaches have been developed to treat this problem. The Matsika group is developing appropriate methods that can treat metastable states and their chemical reactivity taking advantage of the knowledge of excited state reactivity. Specific goals of this work are to develop and test of efficient multireference methods for resonances. The complex absorbing potential approach is used in combination with multireference configuration interaction (MRCI) to obtain both the energies and lifetimes of these states. The performance of the complex absorbing potential method (CAP) is compared with that of orbital stabilization methods for medium sized molecules in combination with various electronic structure methods. Gradients and nonadiabatic couplings for CAP/MRCI are developed. These methods are used to explore complex potential energy surfaces and conical intersections between complex surfaces. The developed methods are used to study electron-driven processes related to radiation damage in nucleobases and the formation of organic molecules in the interstellar medium. The methodology is being implemented in publicly available computational software. Students with a range of backgrounds and levels of academic preparation contribute to this work.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.

天普大学的 Spiridoula Matsika 教授获得化学系化学理论、模型和计算方法项目的奖项支持，致力于开发和应用理论方法来更好地理解电子驱动过程。热、光（光子）和电子提供不同的途径来引发化学反应。 虽然热和光子驱动的化学过程得到了很好的研究，但电子驱动的过程还没有得到很好的理解，尽管电子在自然界中无处不在。电子由辐射产生，它们与原子和分子的碰撞在生物学、化学以及技术中至关重要。电子驱动现象的例子可以在星际化学、辐射化学、环境化学、废物储存库的稳定性、微电子器件材料的等离子体处理以及其他应用中找到。电子驱动过程的一个主要复杂因素是所涉及的状态是亚稳态的。 Matsika 和她的研究小组开发了计算和理论方法来处理亚稳态及其化学反应性。他们专门应用这些方法来更好地了解辐射造成的 DNA 损伤以及星际介质中益生元分子的形成。 该研究预计将为理解许多化学领域中重要的电子驱动现象，特别是生物系统和益生元分子的形成提供有价值的见解。这项研究是由本科生、研究生与博士后合作的研究团队进行的。高中生参与研究活动激发学生参与科学。 这种参与对他们的教育和未来的职业前景产生了非常积极的影响。传统的量子化学方法不能应用于研究亚稳态（或共振），并且已经开发了几种方法来解决这个问题。 Matsika 小组正在开发适当的方法，利用激发态反应性的知识来处理亚稳态及其化学反应性。这项工作的具体目标是开发和测试有效的共振多参考方法。复吸收势方法与多参考构型相互作用 (MRCI) 结合使用，以获得这些状态的能量和寿命。 将复合吸收势法（CAP）的性能与中等大小分子的轨道稳定方法并结合各种电子结构方法进行了比较。开发了 CAP/MRCI 的梯度和非绝热耦合。这些方法用于探索复杂的势能表面和复杂表面之间的圆锥相交。 开发的方法用于研究与核碱基辐射损伤和星际介质中有机分子形成相关的电子驱动过程。 该方法正在公开可用的计算软件中实施。 具有不同背景和学术准备水平的学生为这项工作做出了贡献。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。

项目成果

Stabilization of the Triplet Biradical Intermediate of 5‐Methylcytosine Enhances Cyclobutane Pyrimidine Dimer (CPD) Formation in DNA

5-甲基胞嘧啶三联体双自由基中间体的稳定增强了 DNA 中环丁烷嘧啶二聚体 (CPD) 的形成

• DOI: 10.1002/chem.202002834
• 发表时间: 2020-11
• 期刊: Chemistry – A European Journal
• 作者: Lee, Wook;Matsika, Spiridoula
• 通讯作者: Matsika, Spiridoula

A Unique QP Partitioning and Siegert Width Using Real-Valued Continuum-Remover Potential

使用实值连续体去除势的独特 QP 划分和 Siegert 宽度

• DOI: 10.1021/acs.jctc.1c01096
• 发表时间: 2022-05
• 期刊: Journal of Chemical Theory and Computation
• 影响因子: 5.5
• 作者: Sajeev, Y.;Thodika, Mushir;Matsika, Spiridoula
• 通讯作者: Matsika, Spiridoula

Comparative study of methodologies for calculating metastable states of small to medium-sized molecules

计算中小分子亚稳态方法的比较研究

• DOI: 10.1063/1.5134700
• 发表时间: 2019-12
• 期刊: The Journal of Chemical Physics
• 作者: Thodika, Mushir;Fennimore, Mark;Karsili, Tolga N. V.;Matsika, Spiridoula
• 通讯作者: Matsika, Spiridoula

Intersystem crossing in the exit channel

出口通道中的系间穿越

• DOI: 10.1038/s41557-018-0186-5
• 发表时间: 2018-12-10
• 期刊: Nature Chemistry
• 影响因子: 21.8
• 作者: Hongwei Li;Ale;er Kamasah;er;S. Matsika;A. Suits
• 通讯作者: A. Suits

The origin of fluorescence in DNA thio-analogues

DNA 硫代类似物的荧光起源

• DOI: 10.1016/j.chemphys.2018.08.049
• 发表时间: 2018-11
• 期刊: Chemical Physics
• 影响因子: 2.3
• 作者: Karsili, Tolga N.V.;Thodika, Mushir;Nguyen, Linh;Matsika, Spiridoula
• 通讯作者: Matsika, Spiridoula