In Yambo’s RPA/BSE calculations, I want to use spin-, k- and band-resolved QP (qusi-particle) corrections obtained using another GW code (WEST code). Could anyone tell me how to do that?

Personally, I tried to modify the PWSCF output files eigenval1(2).xml to add state-resolved QP corrections onto the stored eigen energies. However, I found that with the modified eigenval1(2).xml files, the calculated RPA absorption spectra by Yambo has right peak positions but wrong (low) peak heights or amplitudes.

Please find the attached figure to see the problem. In the figure, I compared three Yambo RPA spectra: (i) grey - no QP corrections; (ii) red - QP corrections set by KfnQP_up_E and KfnQP_dn_E; (iii) blue – QP corrections are added to eigenval1(2).xml files of PWSCF. The studied system is a supercell of h-BN with a defect. The first peak in the spectra corresponds to a transition between two defect states.

Could anyone help to explain why adding QP corrections to PWSCF output files eigenval1(2).xml does not work? Is this trouble related to a kind of sum rule?

I also attached one RPA input file using variables KfnQP_up_E and KfnQP_dn_E.

Code: Select all

```
rim_cut # [R RIM CUT] Coulomb potential
optics # [R OPT] Optics
bse # [R BSE] Bethe Salpeter Equation.
bsk # [R BSK] Bethe Salpeter Equation kernel
bss # [R BSS] Bethe Salpeter Equation solver
RandQpts= 100000 # [RIM] Number of random q-points in the BZ
RandGvec= 10 RL # [RIM] Coulomb interaction RS components
CUTGeo= "box z" # [CUT] Coulomb Cutoff geometry: box/cylinder/sphere X/Y/Z/XY..
% CUTBox
0.0 | 0.0 | 19.0 | # [CUT] [au] Box sides
%
CUTRadius= 0.000000 # [CUT] [au] Sphere/Cylinder radius
CUTCylLen= 0.000000 # [CUT] [au] Cylinder length
BSEmod= "retarded" # [BSE] resonant/retarded/coupling
BSKmod= "Hartree" # [BSE] IP/Hartree/HF/ALDA/SEX
BSSmod= "d" # [BSS] (h)aydock/(d)iagonalization/(i)nversion/(t)ddft`
BSENGBlk= 1 Ry # [BSK] Screened interaction block size
% KfnQP_up_E
3.200000 | 1.000000 | 1.000000 | # [EXTQP BSK BSS] E parameters UP (c/v) eV|adim|adim
%
% KfnQP_dn_E
3.800000 | 1.000000 | 1.000000 | # [EXTQP BSK BSS] E parameters UP (c/v) eV|adim|adim
%
WRbsWF
% BEnRange
0.00000 | 9.00000 | eV # [BSS] Energy range
%
% BDmRange
0.02000 | 0.02000 | eV # [BSS] Damping range
%
BEnSteps= 9001 # [BSS] Energy steps
% BLongDir
1.000000 | 0.000000 | 0.000000 | # [BSS] [cc] Electric Field
%
% BSEBands
131 | 162 | # [BSK] Bands range
%
```