Unable to get the smooth bands while interpolating bands using ypp

[Bramhachari Khamari]

Dear Sir,
I have performed a calculation using G0W0 without any error using 5.0 version. However, while interpolating band using ypp I am not getting smooth bands along high symmetry lines that are set in ypp.in. When I increase (BANDS_steps= # Number of divisions ), I get the band structure which is not smooth rather looks like a steps kind of function. My input for the ypp as follows


electrons # [R] Electronic properties
infver # [R] Input file variables verbosity
bnds # [R] Bands
INTERP_mode= "NN" # Interpolation mode (NN=nearest point, BOLTZ=boltztrap aproach)
OutputAlat= 0.000000 # [a.u.] Lattice constant used for "alat" ouput format
cooIn= "rlu" # Points coordinates (in) cc/rlu/iku/alat
cooOut= "rlu" # Points coordinates (out) cc/rlu/iku/alat
% BANDS_bands
21 | 30 | # Number of bands
%
INTERP_Shell_Fac= 20.00000 # The bigger it is a higher number of shells is used
INTERP_NofNN= 1 # Number of Nearest sites in the NN method
CIRCUIT_E_DB_path= "none" # SAVE obtained from the QE `bands` run (alternative to %BANDS_kpts)
BANDS_path= "G,M,K,G" # High-Symmetry points labels (G,M,K,L...) also using composed positions (0.5xY+0.5xL).
BANDS_steps= 10 # Number of divisions
#BANDS_built_in # Print the bands of the generating points of the circuit using the nearest internal point
GfnQPdb= "" # [EXTQP G] Database action
GfnQP_INTERP_NN= 1 # [EXTQP G] Interpolation neighbours (NN mode)
GfnQP_INTERP_shells= 20.00000 # [EXTQP G] Interpolation shells (BOLTZ mode)
GfnQP_DbGd_INTERP_mode= "NN" # [EXTQP G] Interpolation DbGd mode
% GfnQP_E
0.000000 | 1.000000 | 1.000000 | # [EXTQP G] E parameters (c/v) eV|adim|adim
%
GfnQP_Z= ( 1.000000 , 0.000000 ) # [EXTQP G] Z factor (c/v)
GfnQP_Wv_E= 0.000000 eV # [EXTQP G] W Energy reference (valence)
% GfnQP_Wv
0.000000 | 0.000000 | 0.000000 | # [EXTQP G] W parameters (valence) eV| 1|eV^-1
%
GfnQP_Wv_dos= 0.000000 eV # [EXTQP G] W dos pre-factor (valence)
GfnQP_Wc_E= 0.000000 eV # [EXTQP G] W Energy reference (conduction)
% GfnQP_Wc
0.000000 | 0.000000 | 0.000000 | # [EXTQP G] W parameters (conduction) eV| 1 |eV^-1
%
GfnQP_Wc_dos= 0.000000 eV # [EXTQP G] W dos pre-factor (conduction)
PROJECT_mode= "none" # Instruct ypp how to project the DOS. ATOM, LINE, PLANE.
%BANDS_kpts # K points of the bands circuit
0.00000 |0.00000 |0.00000|
0.50000 |0.00000 |0.00000|
0.66666 |-.33333 |0.00000|
0.00000 |0.00000 |0.00000|
%
Any help will be highly appreciated.

Regards,

[Daniele Varsano]

Dear Bramhachari,
first note your input is calculating KS band structure and not GW. To read GW energies you need to set:

Code: Select all

GfnQPdb= " E < $PATH/ndb.QP"

! where $PATH is the SAVE dir or the dir you have the QP database.

About the quality of the interpolation you can also try to change
the interpolation method

Code: Select all

INTERP_mode= "BOLTZ" 

and see if it helps

Best,

Daniele

[Bramhachari Khamari]

Dear Sir,
Thanks a lot for the quick reply.

Regards,