  Comparison is made of the electronic structure of the little-studied layered
transition metal oxide LiNbO$_2$ with that of Na$_x$CoO$_2$, which has
attracted tremendous interest since superconductivity was discovered in its
hydrate. Although the active transition metal $d$ states are quite different
due to different crystal fields and band filling, both systems show a strong
change of electronic structure with changes in the distance between the
transition metal ion layer and the oxygen layers. The niobate is unusual in
having a large second-neighbor hopping amplitude, and a nearest neighbor
hopping amplitude that is sensitive to the Nb-O separation. Li$_x$NbO$_2$ also
presents the attractive simplicity of a single band triangular lattice system
with variable carrier concentration that is superconducting.
