Theoretical Studies of Spin-Forbidden and Electronically Nonadiabatic Processes

自旋禁止和电子非绝热过程的理论研究

基本信息

批准号：
9103299
负责人：
David Yarkony
金额：
$ 20.5万
依托单位：
Johns Hopkins University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1991
资助国家：
美国
起止时间：
1991-06-01 至 1994-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9103299&HistoricalAwards=false
关键词：
Theoretical Studies Spin Forbidden Electronically

项目摘要

With this grant in the Theoretical and Computational Program of the Chemistry Division Professor Yarkony will investigate several problems in spin-forbidden and electronically nonadiabatic chemistry. These processes play a major role in determining the rate of a number of industrially important chemical reactions. Professor Yarkony will develop computer algorithms which will include: (1) the capability for determining relativistic wavefunctions using large scale configuration state function expansions based on quasidegenerate perturbation theory within the Breit-Pauli approximation, and (2) the use of analytical gradient methods for locating regions of significant electronic nonadiabaticity, that is, allowed, avoided and actual crossings of potential energy surfaces, and for determining derivative couplings in these regions. He will consider nonadiabatic electronic quenching reactions such as that between Na+HCl which has been the object of recent experimental and theoretical studies. He will focus on the nature of the adiabatic-diabatic state transformations. Other areas to be investigated include: (1) photochemical dissociation processes, (2) a characterization of the global potential energy surfaces and derivative couplings for the He-H2 system, and (3) a study of spin-forbidden dipole-allowed radiative decay processes in the molecules NO+ and O2+, which are candidates for energy storage intermediates in energy transfer in chemical lasers, as well as the molecules SiCl2, SiH2, and SiHCl which play a role in semiconductor fabrication through vapor deposition.

通过化学部理论和计算项目的这笔资助，Yarkony 教授将研究自旋禁阻和电子非绝热化学中的几个问题。这些过程在确定许多工业上重要的化学反应的速率方面发挥着重要作用。 Yarkony 教授将开发计算机算法，其中包括：(1) 使用基于 Breit-Pauli 近似内的准边生成微扰理论的大规模配置状态函数展开来确定相对论波函数的能力，以及 (2) 使用解析梯度方法进行定位具有显着电子非绝热性的区域，即允许、避免和实际穿过势能表面，并用于确定这些区域中的导数耦合。他将考虑非绝热电子猝灭反应，例如 Na+HCl 之间的反应，这一直是最近实验和理论研究的对象。他将重点关注绝热-非绝热状态转换的本质。其他要研究的领域包括：(1) 光化学解离过程，(2) He-H2 系统的全局势能表面和导数耦合的表征，以及 (3) 自旋禁偶极子允许的辐射衰变的研究NO+ 和 O2+ 分子（它们是化学激光器能量转移中能量存储中间体的候选者）以及分子 SiCl2、SiH2 和 SiHCl（它们通过气相沉积在半导体制造中发挥作用）中的过程。