The fermi level downshifted below VBM when using GW method
Posted: Tue Jun 18, 2013 5:06 pm
Hello everyone,
I am calculating the band structure of bulk Bi2Te3 using GW method. I have recompiled the vasp code with vasp2wannier included and the band structure was calculated using wannier interpolation. The topology of the band structure with GW is almost same as the one without GW, but the Fermi level is not correct. That is, the Fermi level is now ~0.25 eV below the original VBM site. Could anyone give me some suggestion?
The following are the wannier90.win file and the INCAR file in the last step I use:
INCAR:
ISPIN = 2
LSORBIT = .TRUE.
ISMEAR = 0
SIGMA = 0.05
LORBIT = 11
NPAR = 16
EDIFF = 1E-8
NBANDS = 288
EMIN = -20; EMAX = 20
NEDOS=2000
ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 288
PRECFOCK = Fast
NKRED = 3
LWANNIER90=.TRUE.
wannier90.win:
num_wann=30
num_bands=60
num_iter = 200
# for GW uncomment
exclude_bands 1-10,71-288
#kmesh_tol = 0.0000001
#use_bloch_phases = T
Begin Projections
Bi:px;py;pz
Te:px;py;pz
End Projections
dis_win_max = 10.0
dis_froz_max = 7
dis_mix_ratio = 1.0
#dis_froz_max=20
dis_num_iter= 1000
spinors = .true.
#guiding_centres=true
# Bandstructure plot
restart = plot
bands_plot = true
begin kpoint_path
G 0.00000 0.00000 0.0000 Z 0.50000 0.50000 0.5000
Z 0.50000 0.50000 0.5000 F 0.50000 0.50000 0.0000
F 0.50000 0.50000 0.0000 G 0.00000 0.00000 0.0000
G 0.00000 0.00000 0.0000 L 0.00000 0.50000 0.0000
end kpoint_path
bands_num_points 40
bands_plot_format gnuplot xmgrace
begin unit_cell_cart
2.1909999999999998 -1.2649999999999999 10.1579999999999995
0.0000000000000000 2.5299999999999998 10.1579999999999995
-2.1909999999999998 -1.2649999999999999 10.1579999999999995
end unit_cell_cart
begin atoms_frac
Bi 0.4002480527838191 0.4002475805055647 0.4002480685003403
Bi 0.5997519485504189 0.5997524155539223 0.5997519357215851
Te -0.0000000014683620 0.0000000026871744 -0.0000000028952512
Te 0.2089282289616552 0.2089253259473623 0.2089276850399828
Te 0.7910717711724687 0.7910746753059763 0.7910723136333432
end atoms_frac
mp_grid = 6 6 6
begin kpoints
0.000000000000 0.000000000000 0.000000000000
0.166666666667 0.000000000000 0.000000000000
0.333333333333 0.000000000000 0.000000000000
......
end kpoints
I am calculating the band structure of bulk Bi2Te3 using GW method. I have recompiled the vasp code with vasp2wannier included and the band structure was calculated using wannier interpolation. The topology of the band structure with GW is almost same as the one without GW, but the Fermi level is not correct. That is, the Fermi level is now ~0.25 eV below the original VBM site. Could anyone give me some suggestion?
The following are the wannier90.win file and the INCAR file in the last step I use:
INCAR:
ISPIN = 2
LSORBIT = .TRUE.
ISMEAR = 0
SIGMA = 0.05
LORBIT = 11
NPAR = 16
EDIFF = 1E-8
NBANDS = 288
EMIN = -20; EMAX = 20
NEDOS=2000
ALGO = GW0 ; LSPECTRAL = .TRUE. ; NOMEGA = 288
PRECFOCK = Fast
NKRED = 3
LWANNIER90=.TRUE.
wannier90.win:
num_wann=30
num_bands=60
num_iter = 200
# for GW uncomment
exclude_bands 1-10,71-288
#kmesh_tol = 0.0000001
#use_bloch_phases = T
Begin Projections
Bi:px;py;pz
Te:px;py;pz
End Projections
dis_win_max = 10.0
dis_froz_max = 7
dis_mix_ratio = 1.0
#dis_froz_max=20
dis_num_iter= 1000
spinors = .true.
#guiding_centres=true
# Bandstructure plot
restart = plot
bands_plot = true
begin kpoint_path
G 0.00000 0.00000 0.0000 Z 0.50000 0.50000 0.5000
Z 0.50000 0.50000 0.5000 F 0.50000 0.50000 0.0000
F 0.50000 0.50000 0.0000 G 0.00000 0.00000 0.0000
G 0.00000 0.00000 0.0000 L 0.00000 0.50000 0.0000
end kpoint_path
bands_num_points 40
bands_plot_format gnuplot xmgrace
begin unit_cell_cart
2.1909999999999998 -1.2649999999999999 10.1579999999999995
0.0000000000000000 2.5299999999999998 10.1579999999999995
-2.1909999999999998 -1.2649999999999999 10.1579999999999995
end unit_cell_cart
begin atoms_frac
Bi 0.4002480527838191 0.4002475805055647 0.4002480685003403
Bi 0.5997519485504189 0.5997524155539223 0.5997519357215851
Te -0.0000000014683620 0.0000000026871744 -0.0000000028952512
Te 0.2089282289616552 0.2089253259473623 0.2089276850399828
Te 0.7910717711724687 0.7910746753059763 0.7910723136333432
end atoms_frac
mp_grid = 6 6 6
begin kpoints
0.000000000000 0.000000000000 0.000000000000
0.166666666667 0.000000000000 0.000000000000
0.333333333333 0.000000000000 0.000000000000
......
end kpoints