Hydrogenation and desorption of the bcc compound Ti_0.5Cr_0.6V_1.9 was sequentially followed in the course of a time-resolved in situ neutron diffraction experiment on the D20 high flux diffractometer at the Institut Laue Langevin, Grenoble. From the structural point of view it has been shown that hydrogenation induces a structural type of transformation from bcc (starting alloy) to fcc (hydride). This structural transformation has been analyzed as well as the stability range of the metal-hydrogen solid solution (α-hydride). Calculations allowing to quantify the total energy of the alloys and of their parent hydrides were performed. A fairly good agreement was found between the results of experiments and the theoretical derivations in terms of the relative stability of the different materials.