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phDOS and a2F not matching
Posted: Tue Mar 28, 2023 6:46 pm
by simba2828
Dear EPW Users and developer,
What can be the possible reason that my a2F and phDOS are not in good agreement?
I am attaching the figure showing the two quantities, kindly let me know what could be done to match them. I am using fine grids of k 120 120 1 and of q 120 120 1.
Sincerely,
Shubham
Re: phDOS and a2F not matching
Posted: Thu Mar 30, 2023 4:32 pm
by hlee
Dear simba2828:
Could you provide us with all relevant inputs and outputs?
Sincerely,
H. Lee
Re: phDOS and a2F not matching
Posted: Sat Apr 01, 2023 2:47 pm
by simba2828
Dear Lee,
The phonon scf and el-ph inputs are:
(Using Norm-conserving Pseudopotentials)
Code: Select all
&CONTROL
calculation = "scf"
verbosity='high'
restart_mode = 'from_scratch',
prefix = 'nsms',
pseudo_dir = '../../pseudo/',
outdir = './out/'
/
&SYSTEM
a = 3.31634e+00
c = 3.19807e+01
degauss = 0.02
ecutwfc = 100
ibrav = 4
nat = 6
ntyp = 4
occupations = "smearing"
smearing = "gaussian"
/
&ELECTRONS
conv_thr = 1.00000d-10
electron_maxstep = 200
mixing_beta = 0.7D0
diagonalization='david'
mixing_mode = 'plain'
/
ATOMIC_SPECIES
---
ATOMIC_POSITIONS {angstrom}
----
K_POINTS {automatic}
12 12 1 0 0 0
el-ph input:
Code: Select all
&inputph
tr2_ph=1.0d-14,
prefix='nsms',
fildvscf = 'dvscf',
outdir='./out/',
fildyn='nsms.dyn',
electron_phonon='interpolated',
el_ph_sigma=0.05,
el_ph_nsigma=10,
trans=.true.,
ldisp=.true.,
alpha_mix(1)=0.2,
nq1=3, nq2=3, nq3=1
/
The scf input for EPW is similar to phonon scf input and nscf input is just on an explicit grid.
EPW input:
Code: Select all
--
&inputepw
prefix = 'nsms',
amass(1) = 92.90638,
amass(2) = 78.96000,
outdir = './out/'
ep_coupling = .true.
elph = .true.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.
!etf_mem = 1
nbndsub = 17,
!nbndskip = 0
bands_skipped = 'exclude_bands = 1:12,30,31'
wannierize = .false.
num_iter = 500
dis_froz_max= 4.6
dis_froz_min= -5.8
wdata(1) = 'dis_mix_ratio = 0.5'
wdata(2) = 'dis_num_iter = 2000'
wdata(3) = 'bands_plot : true'
wdata(4) = 'bands_num_points : 300'
wdata(5) = 'bands_plot_format : xmgrace gnuplot'
wdata(6) = 'begin kpoint_path'
wdata(7) = 'M 0.5 0.0 0.0 K 0.3333 0.3333 0.0'
wdata(8) = 'K 0.3333 0.3333 0.0 G 0.0 0.0 0.0'
wdata(9) = 'G 0.0 0.0 0.0 M 0.5 0.0 0.0'
wdata(10) = 'end kpoint_path'
iverbosity = 2
eps_acustic = 0.1 ! Lowest boundary for the phonon frequency
ephwrite = .true. ! Writes .ephmat files used when Eliasberg = .true.
nsmear = 1
delta_smear = 0.01 ! eV 0.04
degaussq = 0.5 ! meV
nqstep = 500
eliashberg = .true.
laniso = .true.
limag = .true.
lpade = .true.
!lifc = .true.
!band_plot=.true. ! wannier-bands
!efermi_read = .true.
!fermi_energy = -1.779
fermi_plot = .true.
conv_thr_iaxis = 1.0d-3
!nstemp = 1 ! Nr. of temps
!temps = 15.00 ! K provide list of temperetures OR (nstemp and temps = tempsmin tempsmax for even space mode)
temps(1) = 30
temps(2) = 35
temps(3) = 40
!temps(4) = 25
nsiter = 500
degaussw = 0.04 ! eV ~ 1/4 of fsthick
wscut = 0.4 ! eV 10 times of Upper limit over frequency integration/summation in the Elisashberg eq(1 cm-1 ~ 1/8000 eV)
fsthick = 0.5 ! eV ~ 4 times the maximum phonon frequency
muc = 0.1
dvscf_dir = '../ph/save'
!system_2d = .true.
nk1 = 12
nk2 = 12
nk3 = 1
nq1 = 3
nq2 = 3
nq3 = 1
mp_mesh_k = .true.
nkf1 = 120
nkf2 = 120
nkf3 = 1
nqf1 = 120
nqf2 = 120
nqf3 = 1
/
The energy in scf successfully converged.
The EPW output:
Wannier spreads:
Code: Select all
Running Wannier90
Wannier Function centers (cartesian, alat) and spreads (ang):
( 0.52860 0.30850 3.28954) : 2.91040
( -0.01941 0.52990 0.62406) : 3.29941
( -0.50699 0.28662 0.98432) : 1.95270
( 0.53045 0.30403 0.98592) : 4.02847
( 0.42110 0.33415 2.47315) : 2.92723
( 0.05916 0.57557 1.43594) : 4.18362
( -0.49837 0.84791 2.88407) : 4.25075
( -0.48324 0.25313 2.46049) : 2.89389
( 0.94054 0.58254 1.32918) : 3.09406
( 0.46078 0.32498 3.31057) : 2.92685
( 0.11614 0.59042 0.77775) : 8.90613
( 0.01948 0.58563 0.52250) : 2.83155
( 0.35754 0.79680 1.12665) : 17.07938
( 0.07582 0.84352 0.83863) : 6.48211
( 0.01722 0.57866 1.37885) : 3.03082
( -0.48638 0.24137 3.28777) : 2.89536
( -0.94327 -0.57897 2.49834) : 2.97238
-------------------------------------------------------------------
WANNIER : 49.44s CPU 50.84s WALL ( 1 calls)
-------------------------------------------------------------------
Calculating kgmap
Progress kgmap: ########################################
kmaps : 0.73s CPU 1.82s WALL ( 1 calls)
Code: Select all
Progression iq (fine) = 14200/ 14400
Progression iq (fine) = 14300/ 14400
Progression iq (fine) = 14400/ 14400
Fermi level (eV) = 0.667883489617196D+00
DOS(states/spin/eV/Unit Cell) = 0.147168465827109D+01
Electron smearing (eV) = 0.400000000000000D-01
Fermi window (eV) = 0.500000000000000D+00
Finish writing .ephmat files
===================================================================
Memory usage: VmHWM = 834Mb
VmPeak = 4885Mb
===================================================================
Finish writing dos file nsms.dos
Finish writing phdos files nsms.phdos and nsms.phdos_proj
Fermi surface calculation on fine mesh
Fermi level (eV) = 0.667883
5 bands within the Fermi window
===================================================================
Solve anisotropic Eliashberg equations
===================================================================
Finish reading freq file
Fermi level (eV) = 6.6788348962E-01
DOS(states/spin/eV/Unit Cell) = 1.4716846583E+00
Electron smearing (eV) = 4.0000000000E-02
Fermi window (eV) = 5.0000000000E-01
Nr irreducible k-points within the Fermi shell = 2405 out of 2461
4 bands within the Fermi window
Finish reading egnv file
Max nr of q-points = 14064
805,50 56%
Max nr of q-points = 14064
Finish reading ikmap files
Size of allocated memory per pool: ~= 1.4949 Gb
Start reading .ephmat files
Finish reading .ephmat files
a2f file is not found to estimate initial gap: calculating a2f files
Finish reading a2f file
Electron-phonon coupling strength = 1.8074196
Estimated Allen-Dynes Tc = 19.995505 K for muc = 0.10000
Estimated w_log in Allen-Dynes Tc = 12.891461 meV
Estimated BCS superconducting gap = 3.032620 meV
Estimated Tc from machine learning model = 25.660110 K
WARNING WARNING WARNING
The code may crash since tempsmax = 25.000 K is larger than Allen-Dynes Tc = 19.996 K
temp( 1) = 17.00000 K
Solve anisotropic Eliashberg equations on imaginary-axis
Total number of frequency points nsiw( 1) = 43
Cutoff frequency wscut = 0.4004
Size of allocated memory per pool: ~= 1.4949 Gb
Size of allocated memory per pool: ~= 1.4949 Gb
Actual number of frequency points ( 1) = 43 for uniform sampling
Size of allocated memory per pool: ~= 1.4958 Gb
Size of allocated memory per pool: ~= 1.4990 Gb
Size of required memory per pool: ~= 7.4106 Gb
Size of allocated memory per pool: ~= 1.4990 Gb
akeri is calculated on the fly since its size exceedes max_memlt
iter ethr znormi deltai [meV]
1 3.161528E+00 2.680787E+00 3.456038E+00
2 1.756678E-01 2.666673E+00 3.607143E+00
3 1.173026E-01 2.651875E+00 3.754762E+00
4 2.866368E-02 2.641934E+00 3.862371E+00
5 1.505935E-02 2.635263E+00 3.939232E+00
6 1.160137E-02 2.640763E+00 3.873171E+00
7 2.144168E-02 2.633193E+00 3.974200E+00
8 5.025427E-03 2.634561E+00 3.953667E+00
9 2.052838E-04 2.634557E+00 3.953488E+00
10 4.426619E-03 2.633305E+00 3.971049E+00
11 1.256529E-03 2.633636E+00 3.965964E+00
12 7.709848E-04 2.633358E+00 3.969196E+00
13 8.094553E-04 2.633092E+00 3.972491E+00
14 3.659890E-04 2.632953E+00 3.974060E+00
15 8.515549E-04 2.632657E+00 3.977624E+00
16 6.949045E-04 2.632412E+00 3.980559E+00
17 1.317771E-03 2.631954E+00 3.986052E+00
18 1.206770E-03 2.631541E+00 3.991034E+00
19 8.875571E-04 2.631235E+00 3.994733E+00
20 9.139661E-04 2.630917E+00 3.998560E+00
21 3.658255E-04 2.630798E+00 4.000028E+00
22 3.230211E-04 2.630702E+00 4.001283E+00
23 7.318691E-04 2.630479E+00 4.004131E+00
24 5.281245E-04 2.630319E+00 4.006173E+00
25 5.399595E-04 2.630155E+00 4.008275E+00
26 5.785427E-04 2.629987E+00 4.010482E+00
27 5.883726E-04 2.629804E+00 4.012773E+00
28 7.300649E-04 2.629589E+00 4.015570E+00
29 6.870195E-04 2.629387E+00 4.018223E+00
30 5.289478E-04 2.629237E+00 4.020230E+00
31 2.823832E-04 2.629152E+00 4.021331E+00
32 3.885391E-04 2.629041E+00 4.022816E+00
33 3.338970E-04 2.628938E+00 4.024127E+00
34 4.078674E-04 2.628814E+00 4.025719E+00
35 3.793983E-04 2.628698E+00 4.027212E+00
36 3.286585E-04 2.628599E+00 4.028500E+00
37 4.140730E-04 2.628461E+00 4.030178E+00
38 4.815387E-04 2.628308E+00 4.032083E+00
39 4.197186E-04 2.628173E+00 4.033746E+00
40 2.600534E-04 2.628087E+00 4.034790E+00
41 2.195260E-04 2.628016E+00 4.035666E+00
42 2.623691E-04 2.627933E+00 4.036704E+00
43 2.870899E-04 2.627842E+00 4.037839E+00
44 3.161577E-04 2.627745E+00 4.039080E+00
45 3.549629E-04 2.627633E+00 4.040472E+00
46 2.703714E-04 2.627547E+00 4.041532E+00
47 2.173038E-04 2.627479E+00 4.042376E+00
48 2.499306E-04 2.627402E+00 4.043349E+00
49 1.505975E-04 2.627356E+00 4.043930E+00
50 1.829023E-04 2.627302E+00 4.044638E+00
51 2.734025E-04 2.627223E+00 4.045677E+00
52 2.004033E-04 2.627163E+00 4.046452E+00
53 1.518634E-04 2.627120E+00 4.047034E+00
54 2.671786E-04 2.627039E+00 4.048069E+00
55 1.853435E-04 2.626980E+00 4.048805E+00
56 1.851484E-04 2.626924E+00 4.049524E+00
57 2.262582E-04 2.626855E+00 4.050405E+00
58 9.514811E-05 2.626826E+00 4.050782E+00
Convergence was reached in nsiter = 58
Chemical potential (itemp = 1) = 6.6788348962E-01 eV
Temp (itemp = 1) = 17.000 K Free energy = -0.005508 meV
Size of allocated memory per pool: ~= 1.4990 Gb
Size of allocated memory per pool: ~= 1.4981 Gb
Size of allocated memory per pool: ~= 1.4950 Gb
Min. / Max. values of superconducting gap = -0.878615 4.432438 meV
iaxis_imag : 7608.56s CPU 7609.08s WALL ( 1 calls)
Pade approximant of anisotropic Eliashberg equations from imaginary-axis to real-axis
Cutoff frequency wscut = 0.4000
Size of allocated memory per pool: ~= 1.5123 Gb
pade Re[znorm] Re[delta] [meV]
38 2.827459E+00 3.890757E+00
Convergence was reached for N = 38 Pade approximants
....
I checked various combinations of k/q grids, wscut,fsthick, degaussw, muc etc but still no improvement in the a2f and phdos. They are still distinct.
If any other details required kindly let me know.
One more thing, I am getting negative value of Min Superconduction gap. Kindly check the line in the input. Would you like to comment on that?
Code: Select all
Min. / Max. values of superconducting gap = -0.878615 4.432438 meV
iaxis_imag : 7608.56s CPU 7609.08s WALL ( 1 calls)
Shubham
Re: phDOS and a2F not matching
Posted: Thu Apr 06, 2023 4:09 am
by simba2828
Dear H Lee Sir,
Could you please comment on the query? I have performed many trial calculations for el-ph and EPW but the a2F and phDOS is not matching.
Shubham
Re: phDOS and a2F not matching
Posted: Thu Apr 06, 2023 8:14 pm
by hpaudya1
Hi Shubham,
I did not understand what you mean by "did not match". Phdos and a2f are two different quantities calculated using two different equations, and why should they match?
One thing I noticed is that your Wannier spreads are large for some of the projections, is that acceptable? Did you check the DFT bands on the top of the Wannier bands? And also can you confirm that the coarse mesh Fermi energy (scf.out/nscf.out) and fine mesh Fermi energy (epw.out) are close?
Happy EPWing,
Hari
Re: phDOS and a2F not matching
Posted: Sat Apr 08, 2023 4:32 am
by simba2828
Dear Hari Sir,
1. I have seen many papers where authors explicitly mention that phDOS and spectral density function (a2F(w)) both match at some extent.
2. Yes, I checked Wannier bands are matching with the DFT bands. Slight difference can be seen very far from the Fermi level. Will that affect my calculations?
3. Yes, The Fermi energies match in both the cases: nscf/scf: 1.8972 eV , EPW Fermi energy: 1.857049 eV.
Shubham
Re: phDOS and a2F not matching
Posted: Tue Apr 11, 2023 2:51 pm
by hpaudya1
Hi Shubham,
Could you double check your phonon dispersion and the density of states both with QE and EPW? You can use
https://docs.epw-code.org/doc/Inputs.html#band-plot flag to interpolate your band/phonon.
One more thing I noticed is that you have "amass(1) = 92.90638, amass(2) = 78.96000," in your epw input file, however I see "ntyp = 4" in the scf. Could you double check these? I think something is going wrong in your EPW calculation around this.
Happy EPWing,
Hari
Re: phDOS and a2F not matching
Posted: Tue Apr 18, 2023 9:41 am
by simba2828
Dear Hari Sir,
Could you please tell me how I can generate filkf and filqf files which are needed for band_plot to get the phonon bands using EPW?
Thank you
Re: phDOS and a2F not matching
Posted: Tue Apr 18, 2023 11:09 pm
by hpaudya1
Hi Shubham,
Can you check the following post?
viewtopic.php?t=1226
Happy EPWing,
Hari
Re: phDOS and a2F not matching
Posted: Wed Apr 19, 2023 12:54 pm
by simba2828
Yeah Thank you, I was trying the same, and there I had to delete all the brackets and non-arithmetic symbols and I am putting wk = *** as the weight of that k-point. Is that correct?