  The physics of one dimensional optical superlattices with resonant $s$-$p$
orbitals is reexamined in the language of appropriate Wannier functions. It is
shown that details of the tight binding model realized in different optical
potentials crucially depend on the proper determination of Wannier functions.
We discuss the properties of a superlattice model which quasi resonantly
couples $s$ and $p$ orbitals and show its relation with different tight binding
models used in other works.
