Therefore, we selected 30000 snapshots with intervals of 100 steps from the simulation and performed k-medoids clustering with k = 1. Thus, all structures are assigned to the same cluster and the problem only consists in finding the medoid. The obtained medoid structure is an almost perfect equilateral triangle with side lengths of 1.69, 1.69, and 1.70 Bohrs. This is close to the BO structure having side lengths of 1.65 Bohrs. Figure shows the results. All of the 30000 selected nuclear configurations can be perfectly described with a single cluster, i.e., the chosen value of k = 1 is appropriate. Following the discussion above, this means that the three deuterons are equivalent. Furthermore, our analysis shows that the three deuterons in the D + 3 molecule rarely strongly deviate from an equilateral triangular structure.