Electron Propagator Theory and Anion Electronic Structure

在这个由化学部理论和计算化学项目和国际项目部美洲项目资助的项目中，奥尔蒂斯将使用新的量子力学方法解释几种不寻常阴离子的实验结果。这项研究工作将开发新一代电子结构方法用于电子附着和脱离过程的理论建模与旨在测试这些方法和研究实际感兴趣的化学物种的计算相结合。开发的计算机代码将用于处理范围广泛的化学物种，包括“双里德堡”阴离子、两性离子、双阴离子、多阴离子和金属氧化物团簇。对这些化学体系的研究需要实施和使用新的电子传播子方法，这些方法可以处理阴离子状态下的电子关联以及伴随电子脱离而产生的大轨道弛豫效应。准粒子自洽场方法扩展了现有技术，满足了所研究系统的要求。他们还提供了一种替代的电子结构的单电子图像，这是对以前实现的理论所提供的补充。该项目涉及与墨西哥城UNAM的安娜·马丁内斯和她的同事的合作。拟议的研究涉及开发计算电离势和电子亲合势的新的和改进的算法。理论面临的挑战不是简单地复制几个测量的实验数据，而是开发一个与已知数据一致的理论模型，并能够预测随后测量的后果。这里使用的传播子方法，特别是在定量独立粒子模型的新背景下，非常适合洞察和理解的发展。在该项目中开发的由此产生的新的形式体系有望提高精度、改进计算性能以及对计算数据进行更直接的解释。这些方法将应用于目前有实验意义的几个系统，并将供公众普遍使用。在墨西哥与外国合作者一起旅行和工作的学生将获得国际合作的经验，这将加强他们的科学和教育培训。

In this project funded by the Theoretical and Computational Chemistry Program of the Chemistry Division and the Americas Program in the Division of International Programs, Ortiz will interpret experimental results on several types of unusual anions using new quantum mechanical methodology. This research effort combines the development of a new generation of electronic structure methods for theoretical modeling of electron attachment and detachment processes with calculations that aim at testing these approaches and at investigating chemical species of practical interest. The computer codes developed will be used to address a wide range of chemical species, including "double Rydberg" anions, zwitterions, dianions, polyanions, and metal oxide clusters. Study of these chemical systems requires the implementation and use of new electron propagator methods that can treat electron correlation in anionic states as well as large orbital relaxation effects that accompany electron detachment. Quasiparticle self-consistent-field methods extend current techniques and satisfy the demands of the systems under study. They also offer an alternative one-electron picture of electronic structure that is complementary to that provided by previously implemented theories. This project involves a collaboration with Ana Martinez and her coworkers at UNAM in Mexico City.The proposed research involves the development of new and improved algorithms for calculating ionization potentials and electron affinities. The challenge to theory is not simply to reproduce a few measured experimental data, but rather to develop a theoretical model that is consistent with known data and capable of predicting consequences subject to subsequent measurement. The propagator method used here, especially in the novel context of a quantitative independent-particle model, is admirably suited to the development of insight and understanding. The resulting new formalisms developed in this project hold promise for enhanced accuracy, improved computational performance, and more straightforward interpretation of the computed data. These methods will be applied to several systems of current experimental interest and will be available to the public for general use. The students who will travel and work with the foreign collaborators in Mexico will gain experience with international collaboration that will enhance their scientific and educational training.