Autoionizing resonances in time-dependent density functional theory.
Autoionizing resonances in time-dependent density functional theory.
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时间相关密度泛函理论中的自电离共振。
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
N. Maitra
中科院分区：
文献类型：
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作者：
August J. Krueger;N. Maitra
自电离共振所产生的相互作用的约束单激发的连续可以准确地捕获与目前使用的近似含时密度泛函理论（TDDFT），但那些所产生的约束双激发不能。在前一种情况下，我们解释了绝热内核，它没有频率依赖性，还可以产生强烈的频率依赖的共振结构的相互作用的响应函数，不存在于Kohn-Sham响应函数。在绑定双激发的情况下，我们解释说，一个强烈的频率依赖的内核是必要的，并推导出一个作为后验修正通常的绝热近似TDDFT。在弱相互作用的极限下，我们的近似对于一个孤立的共振是精确的，其中一个离散态与一个连续态相互作用。我们推导出一个“Fano TDDFT内核”，再现Fano lineeshape内的TDDFT形式主义，也是一个穿着的内核，操作上的绝热近似。我们说明我们的结果在一个简单的模型系统。
Autoionizing resonances that arise from the interaction of a bound single-excitation with the continuum can be accurately captured with the presently used approximations in time-dependent density functional theory (TDDFT), but those arising from a bound double excitation cannot. In the former case, we explain how an adiabatic kernel, which has no frequency-dependence, can yet generate the strongly frequency-dependent resonant structures in the interacting response function, not present in the Kohn-Sham response function. In the case of the bound double-excitation, we explain that a strongly frequency-dependent kernel is needed, and derive one as an a posteriori correction to the usual adiabatic approximations in TDDFT. Our approximation becomes exact for an isolated resonance in the limit of weak interaction, where one discrete state interacts with one continuum. We derive a "Fano TDDFT kernel" that reproduces the Fano lineshape within the TDDFT formalism, and also a dressed kernel, that operates on top of an adiabatic approximation. We illustrate our results on a simple model system.