Calculated chemical equilibrium abundances of parent molecules in M-, S-, and C-type AGB atmospheres are shown as a function of radius and are compared with abundances derived from observations. Chemical equilibrium calculations include only gaseous species. Observed abundances are indicated by rectangles, whose vertical extent corresponds to the range of observed abundances given in Table 2. Rectangles are located at different radii to facilitate visualization. Empty rectangles correspond to cases in which observed abundances agree with any of the abundances calculated by chemical equilibrium in the 1–10 R_* range (usually the maximum abundance). Filled rectangles are used to indicate cases with a severe disagreement (by several orders of magnitude) between observed and calculated abundances, while we use hatched rectangles to indicate a significantdisagreement (by more than one order of magnitude). The level of disagreement between the observed and maximum calculated abundance is indicated by a vertical line.