Theory of interatomic (intermolecular) Coulombic decay in clusters

原子间（分子间）库仑衰变（ICD）是团簇中内价电离态的一种极其有效的衰变模式，已被申请人和同事从理论上预测[物理]。社会科学[j].中华社会科学，2004(5)。最近，Heidelberg小组的理论发现在一系列壮观的ICD实验中得到了充分的证实[1,3,4]。虽然关于ICD的大部分理论工作都是建立这种现象的普遍性和机制，但最近的实验和理论进展为ICD的研究开辟了新的视野。本建议旨在为该领域最重要的开放性问题提供理论答案。其中包括：如何准确计算多原子和分子簇的总和部分ICD速率？如果两个（或更多）簇亚基中的一个（或更多）是一个分子，那么ICD速率对两个（或更多）簇亚基相对取向的依赖是什么？在多原子和分子簇中，核动力学对ICD的影响是什么？相对论（如自旋-轨道耦合）对ICD的影响是什么？除了ICD之外，在团簇中还可以观察到哪些原子间（分子间）衰变过程？为了回答上述问题，我们建议显著改进现有的从头算方法，以计算电离团簇的相关电子态的能量和衰变率作为团簇几何形状的函数。特别地，我们将使用格林函数方法来计算衰减率。提出的理论研究结果将对解释和指导未来的ICD实验至关重要。

Interatomic (intermolecular) Coulombic decay (ICD) is an extremely efficient decay mode of inner-valence-ionized states in clusters, which has been predicted theoretically by the applicant and co-workers [Phys. Rev. Lett. 79, 4778 (1997)]. Recently, the theoretical findings of the Heidelberg group have found their full confirmation in a series of spectacular ICD experiments [1, 3, 4]. While most of the theoretical work performed on ICD dealt with establishing the generality and the mechanism of the phenomenon, the recent experimental and theoretical progress opens new horizons for the ICD research. The present proposal is aimed to provide theoretical answers for the most important open questions in the field. Among these are:How can one accurately calculate total and partial ICD rates in polyatomic and molecular clusters?What is the dependence of an ICD rate on the relative orientation of two (or more) cluster subunits if one (or more) of these subunits is a molecule?What is the effect of nuclear dynamics on ICD in polyatomic and molecular clusters?What is the effect of relativity (e.g., spin-orbit coupling) on ICD?What interatomic (intermolecular) decay processes, apart from ICD, can be observed in clusters?In order to answer the above questions, we propose to significantly improve the existing ab initio methodology for the calculation of energies and decay rates of the relevant electronic states of the ionized clusters as functions of the cluster geometry. In particular, we shall use the Green¿s function approach for the calculation of the decay rates. The results of the proposed theoretical research will be essential for interpreting and guiding the future ICD experiments.