El-Ph for spin-polarized and noncollinear systems

Questions and doubts about the spin-dependent version of Yambo.

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El-Ph for spin-polarized and noncollinear systems

Postby luonn » Mon Mar 18, 2019 5:01 am

Dear Yambo Developer and Yambo users,

I found some problems in calculating the electron-phonon couplings (qe6.1 and yambo4.2.1).
A. Generate the input files.
1). When the SOC is included, use the uniform grid method is ok. But, use the random q-point method, there is a problem when generating the ndb.elph_gkkp* files, list in the below (test Si):
yambo_ph:
_| _| _|_| _| _| _|_|_| _|_|
_| _| _| _| _|_| _|_| _| _| _| _|
_| _|_|_|_| _| _| _| _|_|_| _| _|
_| _| _| _| _| _| _| _| _|
_| _| _| _| _| _|_|_| _|_|



<---> [01] CPU structure, Files & I/O Directories
<---> [02] CORE Variables Setup
<---> [02.01] Unit cells
<---> [02.02] Symmetries
<---> [WARNING]Spatial Inversion not found among the given symmetry list
<---> [02.03] RL shells
<03s> [02.04] K-grid lattice
<03s> [02.05] Energies [ev] & Occupations
<03s> [03] Transferred momenta grid
<03s> [RL indx] Q-grid:Electron-Phonon databases
<03s> [RL indx] Q BZ pts are /= from X grid BS pts. Gamma point only.
[get stuck here]
The r_setup file shows:
[03] Transferred momenta grid
=============================

[RL indx] Q-grid:Electron-Phonon databases

IBZ Q-points : 10
BZ Q-points : 53

Q [00001] : -0.08695 -0.16663 -0.44824 (iku) * weight 0.01887
Q [00002] :-0.132335 -0.347009 0.448239 (iku) * weight 0.07547
Q [00003] : 0.166216 0.444148 0.000000 (iku) * weight 0.07547
Q [00004] : 0.05307 -1.18674 0.00000 (iku) * weight 0.150943
Q [00005] : -0.08695 -0.39558 -0.89648 (iku) * weight 0.07547
Q [00006] : 0.166216 0.395579 0.000000 (iku) * weight 0.07547
Q [00007] :-0.132335 1.186736 0.896477 (iku) * weight 0.150943
Q [00008] : 0.166629 -0.395579 -0.347009 (iku) * weight 0.07547
Q [00009] : 0.395579 -1.186736 -0.448239 (iku) * weight 0.150943
Q [00010] :-0.448239 0.448239 -0.448239 (iku) * weight 0.150943

Q [00001] : -0.10609 -0.20329 -0.54687 (cc ) * weight 0.01887
Q [00002] :-0.161453 -0.423364 0.546867 (cc ) * weight 0.07547
Q [00003] : 0.202790 0.541877 0.000000 (cc ) * weight 0.07547
Q [00004] : 0.06475 -1.44786 0.00000 (cc ) * weight 0.150943
Q [00005] : -0.10609 -0.48262 -1.09373 (cc ) * weight 0.07547
Q [00006] : 0.202790 0.482620 0.000000 (cc ) * weight 0.07547
Q [00007] :-0.161453 1.447860 1.093734 (cc ) * weight 0.150943
Q [00008] : 0.203293 -0.482620 -0.423364 (cc ) * weight 0.07547
Q [00009] : 0.482620 -1.447860 -0.546867 (cc ) * weight 0.150943
Q [00010] :-0.546867 0.546867 -0.546867 (cc ) * weight 0.150943
[RL indx] Q BZ pts are /= from X grid BS pts. Gamma point only.

2) For spin-polarized calculations, both the uniform and the random q-point methods have the following problem:
ypp_ph:
___ __ _____ __ __ _____ _____
| Y || _ || Y || _ \ | _ |
| | ||. | ||. ||. | / |. | |
\_ _/ |. _ ||.\_/ ||. _ \ |. | |
|: | |: | ||: | ||: | \|: | |
|::| |:.|:.||:.|:.||::. /|::. |
`--" `-- --"`-- --"`-----" `-----"


<---> [01] CPU structure, Files & I/O Directories
<---> [02] Y(ambo) P(ost)/(re) P(rocessor)
<---> [03] Core DB
<---> :: Electrons : 8.000000
<---> :: Temperature [ev]:0.9500E-3
<---> :: Lattice factors [a.u.]: 5.150000 5.150000 5.150000
<---> :: K points : 3
<---> :: Bands : 30
<---> :: Symmetries : 48
<---> :: RL vectors : 5985
<---> [04] K-point grid
<---> :: Q-points (IBZ): 3
<---> :: X K-points (IBZ): 3
<---> [05] CORE Variables Setup
<---> [05.01] Unit cells
<---> [05.02] Symmetries
<---> [05.03] RL shells
<---> [05.04] K-grid lattice
<---> [05.05] Energies [ev] & Occupations
<---> [06] == Electron-Phonon Interface: PW->Yambo Databases ==
<---> PW(ELPH) databases ...[PHONON] ...incorrect K-point correspondance
<---> [07] Game Over
I have found that someone has asked the same question in the forum (viewtopic.php?f=15&t=1349), has it been fixed?

B. Does the gaussian smearing method in pwscf work for el-ph calculations in yambo?
I find that use gaussian smearing in pwscf for spin nonpolarized calculations (Si) indeed can successfully generate the input files for yambo, but, when I attemp to reproduce the results in yambo tutorials, there is a problem (yambo4.1):
02_OMS.in:
#
# ::: ::: ::: :::: :::: ::::::::: ::::::::
# :+: :+: :+: :+: +:+:+: :+:+:+ :+: :+: :+: :+:
# +:+ +:+ +:+ +:+ +:+ +:+:+ +:+ +:+ +:+ +:+ +:+
# +#++: +#++:++#++: +#+ +:+ +#+ +#++:++#+ +#+ +:+
# +#+ +#+ +#+ +#+ +#+ +#+ +#+ +#+ +#+
# #+# #+# #+# #+# #+# #+# #+# #+# #+#
# ### ### ### ### ### ######### ########
#
#
# GPL Version 4.1.4 Revision 76
# MPI+OpenMP Build
# http://www.yambo-code.org
#
gw0 # [R GW] GoWo Quasiparticle energy levels
el_ph_corr # [R] Electron-Phonon Correlation
SE_Threads= 40 # [OPENMP/GW] Number of threads for self-energy
DysSolver= "n" # [GW] Dyson Equation solver ("n","s","g")
GphBRnge= 8 # [ELPH] G[W] bands range
FANdEtresh=0.1000E-5 eV # [ELPH] Energy treshold for Fan denominator
DWdEtresh=0.1000E-5 eV # [ELPH] Energy treshold for DW denominator
% ElPhModes
1 | 6 | # [ELPH] Phonon modes included
%
GDamping= 0.10000 eV # [GW] G[W] damping
dScStep= 0.10000 eV # [GW] Energy step to evaluate Z factors
ExtendOut # [GW] Print all variables in the output file
RandQpts=100000 # [RIM] Number of random q-points in the BZ
WRgFsq # [ELPH] Dump on file gFsq coefficients
#NewtDchk # [GW] Test dSc/dw convergence
OnMassShell # [F GW] On mass shell approximation
%QPkrange # [GW] QP generalized Kpoint/Band indices
1| 3| 1| 30|
%
%QPerange # [GW] QP generalized Kpoint/Energy indices
1| 3| 0.0|-1.0|
%

o-02.qp
#
# Y88b / e e e 888~~\ ,88~-_
# Y88b / d8b d8b d8b 888 | d888 \
# Y88b/ /Y88b d888bdY88b 888 _/ 88888 |
# Y8Y / Y88b / Y88Y Y888b 888 \ 88888 |
# Y /____Y88b / YY Y888b 888 | Y888 /
# / / Y88b / Y888b 888__/ `88_-~
#
#
# GPL Version 4.1.4 Revision 76
# MPI+OpenMP Build
# http://www.yambo-code.org
#
# GW [Newton Solver]
#
# == El-Ph Self-Energy ==
# [ph] dS/dw steps : 2
# [ph] dS/dw step [ev]: 0.10000
# [ph] Sc/G damping [ev]: 0.10000
# El-Ph correlation : yes
# El-Ph Sc. G bands : 1 8
# El-Ph phonon branches : 1 6
# El-Ph momenta used : 3
# Energy treshold [FAN]:0.1000E-5
# Energy treshold [DW]:0.1000E-5
# QP @ K 001 - 003 : b 001 - 030
#
# K-point Band Eo E E-Eo Z Width[meV]
#
1.00000 1.00000 -12.22806 NaN NaN 1.00000 NaN
1.000000 2.000000 -0.261952 NaN NaN 1.000000 NaN
1.000000 3.000000 -0.261952 NaN NaN 1.000000 NaN
1.000000 4.000000 -0.261952 NaN NaN 1.000000 NaN
1.000000 5.000000 2.154991 NaN NaN 1.000000 NaN
1.000000 6.000000 2.154991 NaN NaN 1.000000 NaN
1.000000 7.000000 2.154991 NaN NaN 1.000000 NaN
1.000000 8.000000 2.976995 NaN NaN 1.000000 NaN
....
I do not know why the calculated qp energy and the width are wrong?

Could you please to give me any suggestions?
thank you very much

Best regards,

Nannan Luo
Nannan Luo
Low-Dimensional Materials and Devices Laboratory,
Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University
C2-7, iPark, Nanshan district, Shenzhen, Guangdong province, China 518055
Tel: (+86)18811369291
E-mail: luo-nn@sz.tsinghua.edu.cn
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luonn
 
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