These six values are determined as follows, given some ion represented by its MS/MS data x. Each tool τ ∈ T is given x and returns a molecule ιτ that τ considers as the closest to x, as well as a match score cτ between x and the spectrum of the molecule ιτ . We retain the value using a very low threshold (cg ≥ 10 -4 ), contrary to common usage.