Theory of interatomic (intermolecular) Coulombic decay in clusters

原子间（分子间）库仑衰变（ICD）是簇中的内价电离态的极其有效的衰变模式，其已经由申请人及其同事在理论上预测[Phys.Rev.Lett. 79，4778（1997）]。最近，海德堡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]。虽然对ICD进行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研究开辟了新的视野。本建议旨在为该领域最重要的开放问题提供理论答案。其中包括：如何准确计算多原子和分子簇中的总ICD率和部分ICD率？如果两个（或多个）簇亚基中的一个（或多个）是一个分子，那么ICD速率对这些亚基的相对取向的依赖性是什么？在多原子和分子团簇中，核动力学对ICD的影响是什么？相对论的影响是什么（例如，自旋轨道耦合）的ICD？除了ICD之外，在团簇中还能观察到哪些原子间（分子间）衰变过程？为了回答上述问题，我们建议显着改善现有的从头计算方法的能量和衰变率的电离团簇的相关电子态的团簇几何形状的函数。特别是，我们将使用绿色函数方法来计算衰减率。理论研究的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.