Theoretical Studies of Spectroscopy and Dynamics of Molecular Systems

光谱学和分子系统动力学的理论研究

• 批准号: 0348858
• 负责人: Hua Guo
• 金额: $ 37.5万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0348858&HistoricalAwards=false
• 关键词: Theoretical; Studies; Spectroscopy; Dynamics; Molecular

Hua Guo of the University of New Mexico is supported by the Theoretical and Computational Chemistry Program to develop accurate and efficient methods to study highly excited spectroscopy and reaction dynamics of small molecular systems. Methods to be employed are based on recursive generation of the Krylov subspace in which the eigenproblem is partially solved. Since the major computational task involves matrix-vector multiplications, such methods have favorable scaling laws. With prudently chosen discretization schemes, recursive methods such as the Lanczos algorithm or the Chebyshev propagation allow efficient computation of highly excited ro-vibrational levels as well as reaction probabilities, cross sections, and rates of systems affected by long-lived resonances. The prototypical system methylene, of interest due to the presence of Renner-Teller coupling and several conical intersections, will be studied using high level at initio calculations including a new strategy. The other system to be investigated is acetylene and its higher energy vinylidene isomer. To characterize this fundamental isomerization in full dimension, a new scheme will be applied to converge all vibrational levels below the isomerization barrier.This research is at the cutting edge of theoretical chemical physics, with outcomes expected to provide valuable insights into experimental observations of important molecular systems and associated chemical processes. As well, computational methodologies will be advanced in general, with computer codes resulting from the research to be made freely accessible to interested researchers. Since this project deals with large eigen or linear equation solvers, outcomes may benefit other fields in science and engineering where similar problems emerge. Examples include but are not limited to high-resolution imaging, nanomaterials, photonic crystals, and biophysics.

新墨西哥大学的郭华在理论和计算化学项目的支持下，开发了准确和高效的方法来研究小分子体系的高激发光谱和反应动力学。所采用的方法是基于Krylov子空间的递归生成，在该Krylov子空间中特征问题被部分求解。由于主要的计算任务涉及矩阵-向量乘法，因此这种方法具有良好的标度律。通过谨慎选择离散化方案，递归方法，如Lanczos算法或切比雪夫传播，允许有效地计算高激发振动能级以及受长寿命共振影响的系统的反应几率、截面和速率。由于Renner-Teller耦合和几个锥形交叉点的存在，将使用包括新策略在内的高水平初始计算来研究原型系统亚甲基。另一个要研究的体系是乙炔及其高能亚乙叉异构体。为了全面描述这种基本的异构化反应，将应用一种新的方案来收敛异构化势垒以下的所有振动能级。这项研究处于理论化学物理的前沿，其结果有望为重要分子体系和相关化学过程的实验观察提供有价值的见解。此外，计算方法将在总体上得到改进，研究产生的计算机代码将免费提供给感兴趣的研究人员使用。由于这个项目涉及大型本征或线性方程解算器，结果可能会使出现类似问题的科学和工程领域的其他领域受益。例子包括但不限于高分辨率成像、纳米材料、光子晶体和生物物理学。