Partly occupied Wannier functions: Construction and applications

Partly occupied Wannier functions: Construction and applications

Partly occupied Wannier functions.

We introduce a scheme for constructing partly occupied, maximally localized Wannier functions (WFs) for both molecular and periodic systems. Compared to the traditional occupied WFs the partly occupied WFs possess improved symmetry and localization properties achieved through a bonding-antibonding closing procedure. We demonstrate the equivalence between bonding-antibonding closure and the mini...

4 Wannier Functions and Construction of Model Hamiltonians

5 Examples of applications 16 5.1 Wide versus narrow energy window: SrVO3 . . . . . . . . . . . . . . . . . . . 17 5.2 Unfolding band structures: LaOFeAs . . . . . . . . . . . . . . . . . . . . . . . 18 5.3 Entangled bands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.4 Spin-orbit coupling: Sr2IrO4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5.5 Wannier f...

Generalized Wannier Functions

We consider single particle Schrodinger operators with a gap in the energy spectrum. We construct a countable set of exponentially decaying functions, which form a complete, orthonormal basis set for the states below the spectral gap. Each such function is localized near a closed surface. Estimates on the exponential decay rate and a discussion of the geometry of these surfaces is included.

Maximally localized Wannier functions for GW quasiparticles

We review the formalisms of the self-consistent GW approximation to many-body perturbation theory and of the generation of optimally localized Wannier functions from groups of energy bands. We show that the quasiparticle Bloch wave functions from such GW calculations can be used within this Wannier framework. These Wannier functions can be used to interpolate the many-body band structure from t...