The output of GW

[sdwang]

Dear all:
What are the "Eo E-Eo Sc(Eo)" in the output file of GW?

Thanks!
SDWang

[myrta gruning]

Dear all:
What are the "Eo E-Eo Sc(Eo)" in the output file of GW?

Thanks!
SDWang

Hallo Shudong Wang

Eo bare energy (coming out from the DFT calculation you input to yambo)
E-Eo difference between quasiparticle energy E and the bare energy Eo, so that is the QP correction
Sc(Eo) Value of the \Sigma_c at Eo

Regards
m

[sdwang]

Thank you for your reply.
That is to say Yambo can calcualte the bare band structurres of DFT (E0)according to scf and nscf of pwscf??( my interface is pwscf)

[Daniele Varsano]

Yes, the DFT band structure is reported, you can easily check it.

Cheers,

Daniele

[myrta gruning]

Hallo
Just a remark.
Yambo is not calculating the DFT band structure, is reporting the DFT energies calculated in the DFT run by (in your case) pwscf in the k mesh you have chosen and that you provide as an input.
As Daniele said, in the report file you find all DFT eigenenergies at each k-point of the mesh. These are just an input of Yambo, not an output.

Regards,
m

[sdwang]

Hallo
Just a remark.
Yambo is not calculating the DFT band structure, is reporting the DFT energies calculated in the DFT run by (in your case) pwscf in the k mesh you have chosen and that you provide as an input.
As Daniele said, in the report file you find all DFT eigenenergies at each k-point of the mesh. These are just an input of Yambo, not an output.

Regards,
m

Thank you!
In the output of GW,there are:
[02.05] Energies [ev] & Occupations
===================================

Fermi Energy[ev] - T[ev/K] : 5.951745 0.000000 0.000000
States summary : Full Metallic Empty
0001-0004 0005-0050
Indirect Gaps [ev]: 1.117994 3.154146
Direct Gaps [ev]: 2.794973 5.387020

For " Indirect Gaps [ev]: 1.117994 3.154146", the 1.117994 is the data of DFT ,and the 3.154146 is the GW data, is it right??

S D Wang

[myrta gruning]

[02.05] Energies [ev] & Occupations
===================================

Fermi Energy[ev] - T[ev/K] : 5.951745 0.000000 0.000000
States summary : Full Metallic Empty
0001-0004 0005-0050
Indirect Gaps [ev]: 1.117994 3.154146
Direct Gaps [ev]: 2.794973 5.387020

For " Indirect Gaps [ev]: 1.117994 3.154146", the 1.117994 is the data of DFT ,and the 3.154146 is the GW data, is it right??

Hallo,

No, both are DFT gaps (relative to the k-grid you have in you calculation).

Note that the report file is organized in sections and subsections.
What you reported is section 2.05
all section 2 is about:

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[02] Input variables setup

The report on the QP part is under

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 [06] Dyson equation: Newton solver

in particular under

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[06.02] Q(uasi)P(article) properties

There you find a part similar to that:

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  QP [eV] @ K [1] (iku): 0.000     0.000     0.000   
   B=19 Eo= -1.56 E= -3.74 E-Eo= -2.18 Z=0.86 So=  2.07418 xx=-18.57731 Vxc=-13.96801
   B=20 Eo= -1.56 E= -3.76 E-Eo= -2.19 Z=0.86 So=  2.06385 xx=-18.57655 Vxc=-13.96766
   B=21 Eo= -1.22 E= -3.31 E-Eo= -2.08 Z=0.86 So=  2.09297 xx=-18.70781 Vxc=-14.19493
   B=22 Eo= -1.22 E= -3.07 E-Eo= -1.85 Z=0.85 So=  1.96251 xx=-17.81735 Vxc=-13.67904
   B=23 Eo=  0.00 E= -1.18 E-Eo= -1.18 Z=0.86 So= 1.177    xx=-16.05    Vxc=-13.50
   B=24 Eo=  0.00 E= -1.18 E-Eo= -1.18 Z=0.86 So=  1.17296 xx=-16.04541 Vxc=-13.50312
   B=25 Eo=  4.39 E=  7.96 E-Eo=  3.57 Z=0.88 So= -0.63854 xx= -7.97938 Vxc=-12.69211
   B=26 Eo=  4.39 E=  7.96 E-Eo=  3.57 Z=0.88 So= -0.63949 xx= -7.97820 Vxc=-12.69144
   B=27 Eo=  5.02 E=  8.66 E-Eo=  3.64 Z=0.89 So= -1.14389 xx= -7.11480 Vxc=-12.33968

where Z is the renormalization factor, xx the Sigma_x matrix element, Vxc the Vxc matrix element and So the Sigma_c matrix element for band B @K[#]

Note as well that the r_* are report files. The output of the calculation (when is human readable) is reported in the o.* files. In this case o.qp.

Regards,
m

[sdwang]

"No, both are DFT gaps (relative to the k-grid you have in you calculation)."
What does this mean?? Why there are two different indirect band gap? I am confused. I hope you can explain it in detail.
Thanks!

[myrta gruning]

Hallo,

Maybe you are confused by the word gap, thinking just about a minimum gap.
Think about Gap as energy difference between a valence and conduction band at a certain k. Then Yambo lists the two lowest gap, both direct and indirect.

Looking in the list of DFT energies at the various k point you have below the

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ndirect Gaps [ev]: 1.117994 3.154146
Direct Gaps [ev]: 2.794973 5.387020

you should be able to find out to which transition these gaps corresponds.

m

[sdwang]

Hallo,

Maybe you are confused by the word gap, thinking just about a minimum gap.
Think about Gap as energy difference between a valence and conduction band at a certain k. Then Yambo lists the two lowest gap, both direct and indirect.

Looking in the list of DFT energies at the various k point you have below the

Code: Select all

ndirect Gaps [ev]: 1.117994 3.154146
Direct Gaps [ev]: 2.794973 5.387020

you should be able to find out to which transition these gaps corresponds.

m

Take the direct gap as a example, is the 2.794973 eV denotes the samllest direct gap ,and the 5.387020 denoyes the most wide direct gap?