Metallicity distribution for the NC members at time t = 0 (black dotted line) and for both NC (red empty histogram) and SC (blue filled histogram) members at time t = 200 Myr, in the innermost 5.5 pc. The observational data from KMOS (see Feldmeier-Krause et al. 2017a) exploited in our companion paper are overlaid on the model (light gray histogram).