Hydrogen is flowed through a mild tesla-coil discharge and trapped at 3.8 K: New infrared absorptions of H-2 are induced by interaction with trapped H atoms and H- anions. High purity parahydrogen and orthodeuterium samples are 1%-9% reconverted depending on the discharge pressure and recombination of atoms. Annealing the solid samples to 7 K reveals growth in p-H-2 induced by o-H-2, which shows that H atom recombination produces thermal nuclear spin populations. Similar results are found in discharge experiments with HD and on annealing solid HD. The observed increase in induced HD absorption by J=1, H-2 and D-2 molecules formed on recombination gives approximate to1% for the H[D] atom concentration in our solid HD samples. (C) 2004 American Institute of Physics.