Both the single-crystal data of Ca(AlH4)2â4THF and the
powder X-ray data of Ca(AlH4)2 show a material with a high
disorder in the lattice, which is not observed with the lighter
and heavier homologues of the tetrahydroaluminate. As the
crystalline THF adduct decomposes into an ultrafine powder
upon drying, the structure is not accessible by single-crystal
methods. Hence, determination of the structure remains a
challenge. To learn more about the local ordering, theoretical
studies and neutron diffraction measurements will be carried
out.