Synthetic spectrum based on the hydrostatic and dust-free initial model (R = 18 000, grey) calculated as described in Sect. 2.2, and some spectra of lower resolutions (as given in the legend) to illustrate the effect of the rebinning on the appearance of the molecular features. In the top panel, the whole spectral range is shown, while the middle panel show the details of a smaller sections. The dashed line marks a calculation where all line contributions were neglected (theoretical continuum level). The bottom panel shows the difference for a spectrum of lower resolution if oversampled by a factor of 10 (magenta) or not (black).