Screened Coulomb interaction in the maximally localized Wannier basis

We discuss a maximally localized Wannier function approach for constructing lattice models from first-principles electronic structure calculations, where the effective Coulomb interactions are calculated in the constrained random-phase-approximation. The method is applied to the 3d transition metals and a perovskite (SrVO_3). We also optimize the Wannier functions by unitary transformation so that U is maximized. Such Wannier functions unexpectedly turned out to be very close to the maximally localized ones.