mirror of https://gitlab.com/QEF/q-e.git
21 lines
1.2 KiB
Plaintext
21 lines
1.2 KiB
Plaintext
In DFT+U, various types of Hubbard projectors can be used.
|
|
In this example we show how to generate localized Wannier functions of
|
|
the relevant bands around the Fermi energy and use them as Hubbard projectors.
|
|
See for instance N.Marzari and D.Vanderbilt, PRB 56, 12847 (1997) and
|
|
I. Sousa, N. Marzari, and D.Vanderbilt, PRB 65, 035109 (2001) for the
|
|
definition and construction of Maximally Localized Wannier Functions (MLWF).
|
|
|
|
Although it is possible to generate MLWF using the WANNIER90 package
|
|
(www.wannier.org), here we follow a simpler prescription and fix the
|
|
phase-factor freedom---intrinsic in any Wannier function determination---
|
|
in a sub-optimal but simple way using the atomic wavefunction as a guide.
|
|
|
|
This is done as a post-processing step with a poormanwannier tool (pmw.x)
|
|
that reads atomic wavefunctions and band structure of an DFT calculation
|
|
and replaces the atomic wavefunctions with our simple Wannier functions.
|
|
|
|
The subsequent DFT+U calculation is performed by specifying "HUBBARD {wf}"
|
|
so that the freshly produced Wannier functions are used in the projection.
|
|
The outcome of this calculation is an insulating state with d-level
|
|
occupations really close to 0 or 1.
|