10.1021/acs.jctc.7b00666.s001 Feizhi Ding Feizhi Ding Takashi Tsuchiya Takashi Tsuchiya Frederick R. Manby Frederick R. Manby Thomas F. Miller Thomas F. Miller Linear-Response Time-Dependent Embedded Mean-Field Theory American Chemical Society 2017 transition properties mean-field TD XAS EMFT sulfur K-edge X-ray absorption spectroscopy TD-EMFT 2017-08-07 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Linear-Response_Time-Dependent_Embedded_Mean-Field_Theory/5357998 We present a time-dependent (TD) linear-response description of excited electronic states within the framework of embedded mean-field theory (EMFT). TD-EMFT allows for subsystems to be described at different mean-field levels of theory, enabling straightforward treatment of excited states and transition properties. We provide benchmark demonstrations of TD-EMFT for both local and nonlocal excitations in organic molecules, as well as applications to chlorophyll a, solvatochromic shifts of a dye in solution, and sulfur K-edge X-ray absorption spectroscopy (XAS). It is found that mixed-basis implementations of TD-EMFT lead to substantial errors in terms of transition properties; however, as previously found for ground-state EMFT, these errors are largely eliminated with the use of Fock-matrix corrections. These results indicate that TD-EMFT is a promising method for the efficient, multilevel description of excited-state electronic structure and dynamics in complex systems.