Neutron diffraction is a powerful tool to elucidate the structure of hydrogen storage materials. HID isotopic substitution was employed to observe the location of deuterium atoms because the coherent scattering length of deuterium is large enough to observe in comparison with those of the other atoms forming hydride materials. The combination of X-ray and neutron diffraction made clear the location of deuterium atoms of the hydrogen induced amorphous alloys experimentally. Moreover, the RMC modeling based on the diffraction data indicates that about 93% of D atoms for a-(Ti0.676Zr0.324)D-0.31 and about 98% of D atoms for a-TbFe2D3.8 and a-TbNi2D2.4 occupy tetrahedral sites formed by metal atoms. Interestingly, during the HIA process, whereas the concentration fluctuation develops in the structure of a-TbFe2D3.0, the homogeneity of the atomic arrangement of metal atoms is kept for a-TbNi2D2.4.