In this work, we present a time-dependent (TD) selected configuration interaction method based on our recently-introduced adaptive configuration interaction (ACI). We show that ACI, in either its ground or excited state formalisms, is capable of building a compact basis for use in real-time propagation of wave functions for computing electron dynamics. TD-ACI uses an iteratively selected basis of determinants in real-time propagation capable of capturing strong correlation effects in both ground and excited states, all with an accuracy---and associated cost---tunable by the user. We apply TD-ACI to study attosecond-scale migration of charge following ionization in small molecules. We first compute attosecond charge dynamics in a benzene model to benchmark and understand the utility of TD-ACI with respect to an exact solution. Finally, we use TD-ACI to reproduce experimentally determined ultrafast charge migration dynamics in iodoacetylene. TD-ACI is shown to be a valuable benchmark theory for electron dynamics, and it represents an important step towards accurate and affordable time-dependent multireference methods.
Exceptionally strong correlation-driven charge migration and attosecond transient absorption spectroscopy
我们从理论上研究了多原子分子（C $_2$ H $_4$ BrI）迅速双电离后的电荷迁移，发现对于双电离，相关驱动的电荷迁移似乎特别突出，即，我们观察到特别丰富的动力学仅由电子-电子相互作用驱动，即使在电子从外价轨道发射的情况下。这些强关联电子动力学在理论上确定的时间分辨瞬态吸收截面见证。引人注目的是，在截面的功能可以追溯到电子空穴人口和时间依赖的部分电荷，因此，可以解释与令人惊讶的容易。值得注意的是，通过利用元素特定的核心到价跃迁，可以在时间和空间上跟踪空穴布居动态。有了这个，我们不仅报告了相关性驱动的电荷迁移的高度相关性，但我们的研究结果也突出了阿秒瞬态吸收光谱（ATAS）作为监测超快电子动力学在复杂的分子系统中最有前途的技术之一的突出作用。
Preparation and control of electronic wave packets in neutral molecules via attosecond x-ray processes
Technical University of Denmark（丹麦技术大学）；University of Hamburg（汉堡大学）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；The Hamburg Centre for Ultrafast Imaging（汉堡超快成像中心）；Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学）；Q-Chem, Inc.（Q-Chem公司）；University of Southern California（南加州大学）
