Geometry Optimization, Reaction Paths and Ab Initio Trajectories. Program Development and Applications

本项目开发和应用量子化学方法得到支持 NSF理论与计算化学计划 改进 方法，包括四阶方法，将被开发用于定位 在从头算势上跟踪反应路径 使用冗余内部坐标的能量曲面，距离 坐标和曲线位移。 对称破坏（两者 空间对称性和自旋对称性）。 应用包括： 利用马库斯理论的自由基抽象反应，重排 涉及环状过渡态的反应，以及 氮化钛气相沉积中间体。 定位静止点的问题，无论是局部极小值还是 过渡态是理论研究中经常遇到的一个问题 新材料的分子结构和化学反应性。 一 该研究项目的主要目标是开发数学方法， 提高了现代计算机的计算效率。 这些 方法将被应用到一些化学问题，也将 可以提供给其他科学家。 特别是，他们将 在广泛使用的高斯代码中实现，用于分子电子 结构计算

This project to develop and apply quantum chemical methods is supported by the NSF Theoretical and Computational Chemistry Program. Improved methods, including a 4th-order method, will be developed for locating stationary points and for following reaction paths on ab initio potential energy surfaces using redundant internal coordinates, distance coordinates, and curvilinear displacements. Symmetry-breaking (both spatial symmetry and spin symmetry) are treated. Applications include: radical abstraction reactions using Marcus theory, rearrangement reactions involving cyclic transition states, and a study of intermediates in titanium nitride vapor deposition. The problem of locating stationary points, either local minima or transition states, is commonly encountered in theoretical investigations of the molecular structure and chemical reactivity of new materials. A major goal of this research project is to develop mathematical methods to improve the efficiency of such computations on modern computers. These methods will be applied to a number of chemical problems, and will also be made available to other scientists. In particular, they will be implemented in the widely used GAUSSIAN codes for molecular electronic structure computation.