Panel a: matrice of confidence levels of the models with respect to the observed abundances of ten COMs relative to H₂. The first four panels in this column show, from top to bottom, the results for Sgr B2(N2), N3, N4, and N5, respectively. Bottom panel: average matrice for all four hot cores taken together. Panel b: same as (a) but only for the O-bearing species CH₃OH, CH₃OCHO, CH₃OCH₃, CH₃CHO, C₂H₅OH, and NH₂CHO. Panel c: same as (a) but only for the cyanides CH₃CN, C₂H₅CN, and C₂H₃CN.