Fractional abundances in the three sources for T < 100 K (cold component, top plot) and T > 100 K (hot component, bottom plot). Red triangles show abundances for G34.3+0.15 (Macdonald et al. 1996), green stars for NGC 6334I, blue stars for G327.3-0.6 (both Schilke et al. 2006) and turquoise stars for 17233–3606 (Leurini et al. 2007). The red lines indicate those molecules where the modeling of different transitions resulted in different column densities (see Tables 34 to 33).