We present results of precise local-density calculations of the electronic structure for the superconducting spinel oxide ${\mathrm{LiTi}}_2$${\mathrm{O}}_4$ as obtained with the full-potential linearized augmented-plane-wave method. Self-consistent calculations are performed for both the observed (distorted) and ideal (undistorted) spinel structures. The results show important changes in the electronic states near $E_F$ between the two structures. Unlike the case of Cu d states in the high-${\mathrm{T}}_{\mathrm{c}}$ Cu-O superconductors, the Ti d bands are separated by an ∼2.6-eV energy gap from the O p bands, and are further split into $t_{2g}$ and $e_g$ bands. The states around $E_F$ have predominant Ti d character, with a substantial hybridization with O p states. Crude rigid-ion calculations indicate that, unlike the case of the Cu-O materials, superconductivity of ${\mathrm{LiTi}}_2$${\mathrm{O}}_4$ can be due to an electron-phonon mechanism.

• Received 27 June 1988

DOI:https://doi.org/10.1103/PhysRevB.38.11352