Infrared spectra of solid hydrogen (deuterium) samples co-deposited at 3.5 K with laser-ablated Al, Ga, In, and Tl atoms reveal infrared absorptions for the MH [MD] molecules. Irradiation at 193 nm increases MH2 and MH3 [MD2 and MD3] absorptions and produces emission spectra for the metal atoms except for Al and phosphorescence spectra for the InH [InD] molecules. Unreacted metal emission bands are blue-shifted from the gas phase more by solid D-2 than by solid H-2. However, the emission yield for InD is much higher in solid D-2 than for InH in solid H-2, which suggests a higher nonradiative relaxation rate in solid H-2 than in solid D-2 owing to the larger zero-point motion.