Simulated absorption spectra for N₂ (black) and H₂ + H (red) in the wavelength range 912–1000 Å assuming thermal excitation temperatures of 50 (top) and 1000 K (bottom). The column density of N₂ is 10¹⁵ cm^-2 and values for H₂ and H are taken to be half of the observed column densities in the well-studied diffuse cloud toward ζ Oph, as is appropriate for the center of the cloud: N(H₂) = 2.1 × 10²⁰ and N(H) = 2.6 × 10²⁰ cm^-2. The model H₂ Doppler width is 3 km s^-1. Also shown is the H₂ + H absorption spectrum (blue) toward ζ Oph using the observed column densities for individual J levels, showing enhanced non-thermal excitation of H₂ in the higher J levels. The asterisks indicate the c′(0) (Band 20) and c(0) (Band 21) bands, respectively, detected in absorption toward HD 124314.