H₂ column densities and ﹩N({{\rm{H}}}_{3}^{+})/N({{\rm{H}}}_{2})﹩ column density ratios predicted for diffuse and translucent molecular clouds with ﹩{\chi }_{\mathrm{UV}}/{n}_{250}=1﹩, where ﹩{\chi }_{\mathrm{UV}}﹩ is the incident radiation field in Draine (1978) units and ﹩{n}_{{\rm{H}}}=250\,{n}_{250}\,{\mathrm{cm}}^{-3}﹩ is the density of H nuclei. Results are shown in the plane of ﹩N({{\rm{H}}}_{2})﹩ and ﹩N({{\rm{H}}}_{3}^{+})/N({{\rm{H}}}_{2})﹩, with contours of visual extinction, ﹩{A}_{{\rm{V}}}(\mathrm{tot})﹩, shown in red and contours of ﹩{\zeta }_{p}({\rm{H}})/{n}_{250}﹩ shown in blue (where ﹩{\zeta }_{p}({\rm{H}})\sim {\zeta }_{t}({{\rm{H}}}_{2})/2.3﹩ is the primary CRIR per H nucleus and ﹩{\zeta }_{t}({{\rm{H}}}_{2})﹩ is the total CRIR per H₂ molecule). Blue contours are labeled with ﹩{\zeta }_{p}({\rm{H}})/{n}_{250}﹩, in units of ﹩{10}^{-16}\,{{\rm{s}}}^{-1}﹩, and red contours with ﹩{A}_{{\rm{V}}}(\mathrm{tot})﹩ in mag. Diamonds, with 1σ error bars, indicate measurements reported by IM12 or Albertsson et al. (2014). Here, black diamonds denote measurements obtained from direct observations of H₂, and magenta diamonds show cases in which the H₂ column densities have been inferred indirectly from observations of CH or ﹩E(B-V)﹩.