Partly occupied Wannier functions.

Partly occupied Wannier functions: Construction and applications

Extended-range computation of Wannier-like functions in amorphous semiconductors

We have computed first-principles occupied Wannier-like functions within an unprecedented spatial range in a realistic model of amorphous Si containing 4096 atoms. To avoid the computation of eigenstates we applied the O(N) Fermi-operator expansion method. The functions decay exponentially in space in a fashion similar to the best-localized occupied Wannier states in crystalline silicon. While ...

Order-N projection method for first-principles computations of electronic quantities and Wannier functions

We present a generalized projection-based order-N method which is applicable within nonorthogonal basis sets of spatially localized orbitals. The projection to the occupied subspace of a Hamiltonian, performed by means of a Chebyshev-polynomial representation of the density operator, allows the nonvariational computation of band-structure energies, density matrices, and forces for systems with ...

Using Wannier functions to improve solid band gap predictions in density functional theory.

Enforcing a straight-line condition of the total energy upon removal/addition of fractional electrons on eigen states has been successfully applied to atoms and molecules for calculating ionization potentials and electron affinities, but fails for solids due to the extended nature of the eigen orbitals. Here we have extended the straight-line condition to the removal/addition of fractional elec...

Dichroic f-sum rule and the orbital magnetization of crystals

We consider the magnetic circular dichroism spectrum of a crystal with broken time-reversal symmetry in the electric-dipole approximation. Using the Kubo-Greenwood formula for the absorptive part of the antisymmetric optical conductivity, its frequency integral is recast as a ground-state property. We show that in insulators this quantity is proportional to the circulation of the occupied Wanni...