Crystal structure of the sodium cobaltate deuterate superconductorNaxCoO2⋅4xD2O(x≈13)

Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition ${\mathrm{Na}}_{0.31(3)}{\mathrm{CoO}}_{2}\ensuremath{\cdot}1.25(2){\mathrm{D}}_{2}\mathrm{O}$ and its anhydrous parent compound ${\mathrm{Na}}_{0.61(1)}{\mathrm{CoO}}_{2}.$ The anhydrous parent compound ${\mathrm{Na}}_{0.61(1)}{\mathrm{CoO}}_{2}$ has two partially occupied Na sites sandwiched, in the sa