Visualizing electronic excitations with the particle-hole map: orbital localization and metric space analysis

摘要

The particle-hole map (PHM) is a computational tool to visualize electronic excitations-calculated using time-dependent density-functional theory-based on representations in canonical molecular orbital transition space. Beyond the standard canonical representation, transformation to localized orbitals is a common technique in electronic structure theory. We analyze the PHM as a visualization tool for both canonical and localized orbital representations and give numerical examples for simple one-dimensional model systems. We show that the localized PHMs can be used to construct simple descriptors of the charge-transfer character of an excitation through metric space analysis, and that it can improve the clarity of the visualization provided by the canonical PHM.