Weakly-bound and metastable anions: Developments of methods and applications

在该项目的第一阶段，对大阴离子的理论研究取得了实质性进展。基于电子传播子理论的大规模并行平台（P-RICD-Sigma）和一种新的复合吸收势，使亚稳阴离子态的计算不需要人工共振。我们已经证明，与高阶耦合簇方法相比，所实现的二阶电子传播子方法具有非常好的性能。介绍了一类新的关联结合阴离子，并对其进行了表征。发现了一种新的协同基本反应机理，并命名为催化电子断键。新开发的方法和代码已成为计算弱结合和亚稳定阴离子的有力工具。我们现在能够完全从头开始攻击相对较大的系统（目前还不能这样做），解决当前感兴趣的有争议的问题，并预测多余电子的新结合机制。未来的项目主要有三个目标。该方法在水簇阴离子上的应用与理解水如何溶剂化电子有关。该结果还需要用于标定模型电位，用于研究液态水。富勒烯阴离子在文献中被广泛研究。是否存在一类新的阴离子态（弱束缚s态）以及它们可能具有什么性质，一直是有争议的讨论。应用所开发的方法可以完全从头开始解决这一争议。此外，还可以确定这些状态的性质和普遍的结合机制。最后但并非最不重要的是，该方法应该进一步发展，并研究其他有趣的例子。

In the first stage of this project substantial progress has been made towards the theoretical study of large anions. A new massively parallel platform based on electron propagator theory (called P-RICD-Sigma) and a new complex absorbing potential which makes the calculations of metastable anionic states free of artificial resonances have been developed. We have demonstrated that the implemented second-order electron propagator method performs extremely well in comparasion with higher order coupled-cluster methods. The new class of correlation-bound anions has been introduced and characterized. A novel concerted elementary reaction mechanism has been discovered and named Bond Breaking by a Catalytic Electron (BBCE). The newly developed method and code have become a powerful tool to compute weakly-bound and metastable anions. We are now in the position to attack relatively large systems fully ab initio (which currently cannot be done otherwise), to solve controversial problems of current interest and to predict new binding mechanisms of an excess electron. The future project has mainly three objectives. The application of the method to water cluster anions is of relevance to the understanding of how water solvates electrons. The results are also needed to calibrate model potentials which can be used to study liquid water. Fullerene anions have been much studied in the literature. Whether a new class of anionic states (weakly-bound s-like states) exists and what properties they may have, has been discussed controversially. The application of the method developed can resolve the controversy fully ab initio. Moreover, the properties and prevailing binding mechanisms of these states can be determined. Last but not least, the method should be further developed and other interesting examples studied.