Prediction and Analysis in Electron Propagator Theory

分子电子结构理论研究项目由国家科学基金理论与计算化学计划资助。从头算电子传播子理论（EPT）被应用于电离势、电子亲和和相关性质的计算。改进的计算机代码EPT计算将开发使用算法改编自从头算理论的其他领域。这些包括计算二阶和三阶准粒子，以及使用直接产生电子排斥积分、密度基集和使用拉普拉斯变换技术消除能量分母的大分子重归一化自能。这些方法将在一个小型工作站集群的并行代码中实现。该理论将应用于多电荷碳簇阴离子和有机金属自由基。像所有从头计算分子电子结构的方法一样，电子传播子理论（EPT）是基于量子力学的基本方程。EPT方程提供了更直接的途径来严格计算电子激发能，从而计算光谱激发、电离能和电子亲和能。这个项目的重点是发展改进的计算方法及其在并行计算机上的实施，特别是在工作站集群上的实施。

This project in molecular electronic structure theory is supported by the NSF Theoretical and Computational chemistry Program. Ab initio electron propagator theory (EPT) is applied to the computation of ionization potentials, electron affinities, and related properties. Improved computer codes for EPT computations will be developed using algorithms adapted from other areas of ab initio theory. These include the computation of second and third-order quasiparticle and renormalized self-energy for large molecules using direct generation of electron-repulsion integrals, density basis sets, and elimination of energy denominators using Laplace transform techniques. These methods will be implemented in parallel code for a small cluster of workstations. The theory will be applied to multiply charged carbon cluster anions and to organometallic radicals. Like all ab initio methods for the calculation of the electronic structure of molecules, electron propagator theory (EPT) is based on the fundamental equations of quantum mechanics. The EPT equations provide a more direct route to the rigorous calculation of electron excitation energies and thus of spectroscopic excitations, ionization energies, and electron affinities. The emphasis in this project is on the development of improved computational methods and their implementation on parallel computers, particularly, on clusters of workstations.