Comparison of \textit{Ab initio} Low-Energy Models for LaFePO, LaFeAsO, BaFe$_{2}$As$_{2}$, LiFeAs, FeSe, and FeTe

We present effective low-energy models for LaFePO and LaFeAsO (1111 family), BaFe$_{2}$As$_{2}$ (122), LiFeAs (111), and FeSe and FeTe (11) [1], based on \textit{ab initio} downfolding scheme, a constrained random-phase-approximation method combined with maximally localized Wannier functions. Comparison among the effective models, derived for 5 Fe-3$d$ bands, provides a basis for interpreting physics/chemistry; material dependences of electron correlations, a multiband character entangled by the 3$d$ orbitals, and the geometrical frustration depending on hybridizations between iron and pnictogen/chalcogen orbitals. We found that LaFePO in the 1111 family resides in the weak correlation regime, while LaFeAsO and 111/122 compounds are the intermediate region and FeSe and FeTe in the 11 family are located in the strong correlation regime. A principal parameter relevant to the physics is clarified to be the pnictogen/chalcogen height from the iron layer. Implications in low-energy properties including magnetism and superconductivity are discussed. [1] T. Miyake, K. Nakamura, R. Arita, and M. Imada, arXiv:0911.3705.