  By breaking the inversion symmetry of the three-dimensional Dirac metal
Na$_3$Bi, we realize topological insulator (TI) phases in the known compound
NaBaBi using $ab~initio$ calculations. Two distinct TI phases emerge: one phase
is due to band inversion between the Bi $p$ and Na $s$ bands, and the other
phase (under pressure) is induced by inversion of the Bi $p$ and Ba $d$ bands.
Both phases exhibit Dirac-cone-type surface states, but they have opposite spin
textures. In the upper cone, a left-handed spin texture exists for the $s$-$p$
inverted phase (similar to a common TI, e.g., Bi$_2$Se$_3$), whereas a
right-handed spin texture appears for the $p$-$d$ inverted phase. NaBaBi
presents a prototype model of a TI that exhibits different spin textures in the
same material. In addition, NaBaBi may exhibit the introduction of correlation
effects to the topological state owing to the existence of $d$ states in the
band inversion.
