Structure of 1T-Li2NiO2 from powder neutron diffraction

The structure of 1T-Li2NiO2 from profile refinement of powder neutron diffraction data is reported. The compound has space group P-3m1, with a=3.0954(9) Å and c=5.070(1) Å. Hexagonally close-packed layers of oxygen alternate with metal atom layers in the sequence O-Ni-O-Li-O-Ni-O-Li …. The nickel atoms fill the octahedral interstices between the more closely spaced pairs of O layers and the Li atoms fill all the tetrahedral sites between the alternate, more separated, oxygen layers.