*Littlewood-Richardson coefficients* $c^\lambda_{\mu\nu}$ have numerous combinatorial interpretations, including the *hive model* by Knutson and Tao, see [here][1]. For other root systems, there are also several combinatorial interpretations, notably the Berenstein and Zelevinsky interpretation in terms of integer points in polytopes, see [here][2]. In the root system A, these are closely related to hives (see KT paper and also [here][3]). Despite extensive googling I can't seem to find the answer to this: **Question**: What are hives for root systems BCD? What am I missing? UPDATE As Gjergji helpfully writes in the comments, this was asked earlier in [this MO question][4]. I am not sure if the answers there resolve the problem (JiaRui Fei's paper comes close, perhaps). However, if there are new answers they should be posted there, so it's best to close this question. [1]: https://arxiv.org/abs/math/9807160 [2]: https://arxiv.org/abs/math/9912012 [3]: https://www.math.ucla.edu/~pak/papers/liri91.pdf [4]: https://mathoverflow.net/questions/33712