Data and post-processing scripts for Phys.Rev.B 100, 085146 (2019)
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DFT+DMFT study of oxygen vacancies in a Mott insulator
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DOI: 10.1103/PhysRevB.100.085146
J. Souto-Casares, N. A. Spaldin, C. Ederer
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Abstract:
Oxygen vacancies are a common source of excess electrons in complex oxides.
In Mott insulators, these additional electrons can induce a metal-insulator
transition (MIT), fundamentally altering the electronic properties of the
system. Here we study the effect of oxygen vacancies in LaTiO3, a prototypical
Mott insulator close to the MIT. We show that the introduction of oxygen
vacancies creates a vacancy-related band immediately below the partially filled
Ti-t 2g bands. We study the effect of this additional band on the Mott MIT
using a combination of density functional theory and dynamical mean-field
theory (DFT+DMFT), employing a minimal correlated subspace consisting of
effective Ti-t 2g orbitals plus an additional Wannier function centered on the
vacancy site. We find that the Mott insulating state in LaTiO 3 is robust to
the presence of the vacancy band, which remains fully occupied even in the
presence of a local Coulomb repulsion, and therefore does not cause a doping
of the Mott insulator

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The compressed tar archive contains a jupyter notebook (https://jupyter.org/) that
will read the data produced by VASP, wannier90, and the triqs DMFT framework
(https://triqs.github.io/triqs/2.1.x/) and post-process it to the figures found
in our publication, after proper redirection of the paths to the needed output files.
All input data is also contained in the archives.
Note: Due to license reasons we had to remove all VASP POTCAR files.
Figure 1 was done using the visualization program VESTA with a light Inkscape
postprocessing to highlight the oxygen vacancy sites.
Figure 2(c) was also done using VESTA; the representation of the oxygen vacancy 
wannier function was plotted from an xsf file produced by Wannier90. 

Basic workflow:
-1-DFT calculation: VASP + Wannier90 to create a wannier90_hr.dat file, containing the 
 tight-binding-like Hamiltonian of the correlated orbitals (Ti-t2g or Ti-t2g+OV).
 VASP bandstructure is extracted from the output files using the script bands.py;
 Wannier90 DOS files are calculated individually and later manipulated with the 
 script merge_wannier_dos.py.
-2-DMFT calculation: Use the Wannier90 converter to create the h5 input file. Define
 the DMFT calculation on the param.py file, and run dmft_cthyb.py. The main output 
 files are called 'observables_imp#.dat'. To calculate the spectral functions we use
 Bryan's maxent algorithm as implemented in
 https://bitbucket.org/lewinboehnke/maxent/src/master.

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