Calculated vertical column densities down to the midplane of H₂O, C₂ H₂, and HCN (left panel) and the radicals C₂H and CN (right panel) as a function of radius r for the T Tauri disk. We show results from our fiducial model, a model in which a 4000 K blackbody stellar spectrum is considered, and a model in which all photodestruction rates are computed using parametric expressions (see text).