The photolysis of hydrogen-containing molecules in noble-gas (Ng) matrices results in hydrogen atoms caged in octahedral interstitial lattice sites. The excited states give rise to characteristic absorption bands and relax most probably into a Ng2H charge-transfer state. A simple model is proposed for calculating the potential of this state and also for the ground state. The results can be compared with new measurements of the photolytically induced fluorescence bands at 5 to 6 eV of H-doped solid noble gases.