*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? [1]: https://arxiv.org/abs/math/9807160 [2]: https://arxiv.org/abs/math/9912012 [3]: https://www.math.ucla.edu/~pak/papers/liri91.pdf