Within the framework of the local-density approximation and the ab ini
tio pseudopotential theory, it is shown that alloying of MgH2 with Li
or Al may be described in terms of the rigid-band model. Metallization
of insulating MgH2 upon doping with Li or Al should therefore be poss
ible. Doping with Li appears to be more favorable both from a thermody
namic point of view as well as from the objective of obtaining a high
density of states at the Fermi level.