The heat of hydride formation was

In the hypo-stoichiometric series of the alloys, ΔH of alloys Y6–Y9 can be obtained and are very similar to that of the Y-free TMC647055 alloy (Y0). The ΔS of these alloys are also very similar. Therefore, uracil seems that the addition of Y in the hypo-stoichiometric series does not change the metal–hydrogen bond and the ordering of the hydride significantly. This result is somewhat unexpected.