Since our original review , the field of Subsystem-DFT (sDFT) and Frozen-Density Embedding (FDE) has grown tremendously. Other general overviews that have been published in the meantime include a review of multilevel electronic-structure simulation methods based on FDE by Wesolowski et al. . A special issue of the International Journal of Quantum Chemistry was devoted to quantum embedding electronic-structure methods; the content is summarized in the editorial in Ref. . Recently, König and coworkers reviewed sDFT and FDE in comparison to classical polarizable embedding schemes .