EPW Forum

Dear Experts,
I am getting zero or infinite values while calculating a2f through epw.I don't know why it is happening.I have enclosed input and output files in the following.Please help me to solve this issue.

--
&inputepw
prefix = 'Graphene',
amass(1) = 12.0107
outdir = './'

elph = .true.
kmaps = .false.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.

nbndsub = 5
nbndskip = 0
wannierize = .true.
num_iter = 300
iprint = 2
dis_win_max = 11.8
dis_froz_max= 0.52
proj(1) = 'f=0,0,0.5:pz'
proj(2) = 'f=0.33333333,0.66666667,0.5:sp2;pz'
system_2d = .true.

wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = 'G 0.00 0.00 0.00 M 0.50 0.00 0.00'
wdata(4) = 'M 0.50 0.00 0.00 K 0.33 0.33 0.00'
wdata(5) = 'K 0.33 0.33 0.00 G 0.00 0.00 0.00'
wdata(6) = 'end kpoint_path'
wdata(7) = 'num_print_cycles = 1'
wdata(8) = 'bands_plot_format = gnuplot'
wdata(9) = 'guiding_centres = .true.'
wdata(10) = 'dis_num_iter = 300'
wdata(11) = 'dis_mix_ratio = 0.2'

iverbosity = 0

elecselfen = .true.
phonselfen = .true.
a2f = .true.

parallel_k = .true.
parallel_q = .false.

fsthick = 5 ! eV
eptemp = 300 ! K
degaussw = 0.025 ! eV
degaussq = 0.05 ! meV

dvscf_dir = './save'
filukk = './Graphene.ukk'

nk1 = 8
nk2 = 8
nk3 = 1

nq1 = 8
nq2 = 8
nq3 = 1

nqf1 = 32
nqf2 = 32
nqf3 = 1

nkf1 = 32
nkf2 = 32
nkf3 = 1

/
10 cartesian
0.000000000 0.000000000 0.000000000
0.000000000 0.144337567 0.000000000
0.000000000 0.288675135 0.000000000
0.000000000 0.433012702 0.000000000
0.000000000 -0.577350269 0.000000000
0.125000000 0.216506351 0.000000000
0.125000000 0.360843918 0.000000000
0.125000000 0.505181486 0.000000000
0.250000000 0.433012702 0.000000000
0.250000000 0.577350269 0.000000000


Output

``:oss/
`.+s+. .+ys--yh+ `./ss+.
-sh//yy+` +yy +yy -+h+-oyy
-yh- .oyy/.-sh. .syo-.:sy- /yh
`.-.` `yh+ -oyyyo. `/syys: oys `.`
`/+ssys+-` `sh+ ` oys` .syo`
-yh- ./syyooyo` .sys+/oyo--yh/
`yy+ .-:-. `-/+/:` -sh-
/yh. oys
``..---hho---------` .---------..` `.-----.` -hd+---.
`./osmNMMMMMMMMMMMMMMMs. +NNMMMMMMMMNNmh+. yNMMMMMNm- oNMMMMMNmo++:`
+sy--/sdMMMhyyyyyyyNMMh- .oyNMMmyyyyyhNMMm+` -yMMMdyyo:` .oyyNMMNhs+syy`
-yy/ /MMM+.`-+/``mMMy- `mMMh:`````.dMMN:` `MMMy-`-dhhy```mMMy:``+hs
-yy+` /MMMo:-mMM+`-oo/. mMMh: `dMMN/` dMMm:`dMMMMy..MMMo-.+yo`
.sys`/MMMMNNMMMs- mMMmyooooymMMNo: oMMM/sMMMMMM++MMN//oh:
`sh+/MMMhyyMMMs- `-` mMMMMMMMMMNmy+-` -MMMhMMMsmMMmdMMd/yy+
`-/+++oyy-/MMM+.`/hh/.`mNm:` mMMd+/////:-.` NMMMMMd/:NMMMMMy:/yyo/:.`
+os+//:-..-oMMMo:--:::-/MMMo. .-mMMd+---` hMMMMN+. oMMMMMo. `-+osyso:`
syo `mNMMMMMNNNNNNNNMMMo.oNNMMMMMNNNN:` +MMMMs:` dMMMN/` ``:syo
/yh` :syyyyyyyyyyyyyyyy+.`+syyyyyyyyo:` .oyys:` .oyys:` +yh
-yh- ```````````````` ````````` `` `` oys
-+h/------------------------::::::::://////++++++++++++++++++++++///////::::/yd:
shdddddddddddddddddddddddddddddhhhhhhhhyyyyyssssssssssssssssyyyyyyyhhhhhhhddddh`

S. Ponce, E. R. Margine, C. Verdi, and F. Giustino,
Comput. Phys. Commun. 209, 116 (2016)


Program EPW v.4.3.0 (svn rev. 14038) starts on 1Aug2018 at 12:47:55

This program is part of the open-source Quantum ESPRESSO suite
for quantum simulation of materials; please cite
"P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
"P. Giannozzi et al., J. Phys.:Condens. Matter 29 465901 (2017);
URL http://www.quantum-espresso.org",
in publications or presentations arising from this work. More details at
http://www.quantum-espresso.org/quote

Parallel version (MPI), running on 4 processors

MPI processes distributed on 1 nodes
K-points division: npool = 4

Reading data from directory:
./Graphene.save/

IMPORTANT: XC functional enforced from input :
Exchange-correlation = PZ ( 1 1 0 0 0 0)
Any further DFT definition will be discarded
Please, verify this is what you really want


G-vector sticks info
--------------------
sticks: dense smooth PW G-vecs: dense smooth PW
Sum 595 595 223 242597 242597 56951


--

bravais-lattice index = 4
lattice parameter (a_0) = 4.6510 a.u.
unit-cell volume = 1795.1721 (a.u.)^3
number of atoms/cell = 2
number of atomic types = 1
kinetic-energy cut-off = 100.0000 Ry
charge density cut-off = 400.0000 Ry
convergence threshold = 0.0E+00
beta = 0.0000
number of iterations used = 0
Exchange-correlation = PZ ( 1 1 0 0 0 0)


celldm(1)= 4.65099 celldm(2)= 0.00000 celldm(3)= 20.60336
celldm(4)= 0.00000 celldm(5)= 0.00000 celldm(6)= 0.00000

crystal axes: (cart. coord. in units of a_0)
a(1) = ( 1.0000 0.0000 0.0000 )
a(2) = ( -0.5000 0.8660 0.0000 )
a(3) = ( 0.0000 0.0000 20.6034 )

reciprocal axes: (cart. coord. in units 2 pi/a_0)
b(1) = ( 1.0000 0.5774 -0.0000 )
b(2) = ( 0.0000 1.1547 0.0000 )
b(3) = ( 0.0000 -0.0000 0.0485 )


Atoms inside the unit cell:

Cartesian axes

site n. atom mass positions (a_0 units)
1 C 12.0117 tau( 1) = ( 0.25000 -0.14434 10.30168 )
2 C 12.0117 tau( 2) = ( 0.75000 0.14434 10.30168 )

2 Sym.Ops. (with q -> -q+G )


G cutoff = 219.1754 ( 242597 G-vectors) FFT grid: ( 30, 30,625)
number of k points= 64 gaussian broad. (Ry)= 0.0020 ngauss = 0
cart. coord. in units 2pi/a_0
k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 0.0312500
k( 2) = ( 0.0000000 0.1443376 0.0000000), wk = 0.0312500
k( 3) = ( 0.0000000 0.2886751 0.0000000), wk = 0.0312500
k( 4) = ( 0.0000000 0.4330127 0.0000000), wk = 0.0312500
k( 5) = ( 0.0000000 0.5773503 0.0000000), wk = 0.0312500
k( 6) = ( 0.0000000 0.7216878 0.0000000), wk = 0.0312500
k( 7) = ( 0.0000000 0.8660254 0.0000000), wk = 0.0312500
k( 8) = ( 0.0000000 1.0103630 0.0000000), wk = 0.0312500
k( 9) = ( 0.1250000 0.0721688 0.0000000), wk = 0.0312500
k( 10) = ( 0.1250000 0.2165064 0.0000000), wk = 0.0312500
k( 11) = ( 0.1250000 0.3608439 0.0000000), wk = 0.0312500
k( 12) = ( 0.1250000 0.5051815 0.0000000), wk = 0.0312500
k( 13) = ( 0.1250000 0.6495191 0.0000000), wk = 0.0312500
k( 14) = ( 0.1250000 0.7938566 0.0000000), wk = 0.0312500
k( 15) = ( 0.1250000 0.9381942 0.0000000), wk = 0.0312500
k( 16) = ( 0.1250000 1.0825318 0.0000000), wk = 0.0312500
k( 17) = ( 0.2500000 0.1443376 0.0000000), wk = 0.0312500
k( 18) = ( 0.2500000 0.2886751 0.0000000), wk = 0.0312500
k( 19) = ( 0.2500000 0.4330127 0.0000000), wk = 0.0312500
k( 20) = ( 0.2500000 0.5773503 0.0000000), wk = 0.0312500
k( 21) = ( 0.2500000 0.7216878 0.0000000), wk = 0.0312500
k( 22) = ( 0.2500000 0.8660254 0.0000000), wk = 0.0312500
k( 23) = ( 0.2500000 1.0103630 0.0000000), wk = 0.0312500
k( 24) = ( 0.2500000 1.1547005 0.0000000), wk = 0.0312500
k( 25) = ( 0.3750000 0.2165064 0.0000000), wk = 0.0312500
k( 26) = ( 0.3750000 0.3608439 0.0000000), wk = 0.0312500
k( 27) = ( 0.3750000 0.5051815 0.0000000), wk = 0.0312500
k( 28) = ( 0.3750000 0.6495191 0.0000000), wk = 0.0312500
k( 29) = ( 0.3750000 0.7938566 0.0000000), wk = 0.0312500
k( 30) = ( 0.3750000 0.9381942 0.0000000), wk = 0.0312500
k( 31) = ( 0.3750000 1.0825318 0.0000000), wk = 0.0312500
k( 32) = ( 0.3750000 1.2268693 0.0000000), wk = 0.0312500
k( 33) = ( 0.5000000 0.2886751 0.0000000), wk = 0.0312500
k( 34) = ( 0.5000000 0.4330127 0.0000000), wk = 0.0312500
k( 35) = ( 0.5000000 0.5773503 0.0000000), wk = 0.0312500
k( 36) = ( 0.5000000 0.7216878 0.0000000), wk = 0.0312500
k( 37) = ( 0.5000000 0.8660254 0.0000000), wk = 0.0312500
k( 38) = ( 0.5000000 1.0103630 0.0000000), wk = 0.0312500
k( 39) = ( 0.5000000 1.1547005 0.0000000), wk = 0.0312500
k( 40) = ( 0.5000000 1.2990381 0.0000000), wk = 0.0312500
k( 41) = ( 0.6250000 0.3608439 0.0000000), wk = 0.0312500
k( 42) = ( 0.6250000 0.5051815 0.0000000), wk = 0.0312500
k( 43) = ( 0.6250000 0.6495191 0.0000000), wk = 0.0312500
k( 44) = ( 0.6250000 0.7938566 0.0000000), wk = 0.0312500
k( 45) = ( 0.6250000 0.9381942 0.0000000), wk = 0.0312500
k( 46) = ( 0.6250000 1.0825318 0.0000000), wk = 0.0312500
k( 47) = ( 0.6250000 1.2268693 0.0000000), wk = 0.0312500
k( 48) = ( 0.6250000 1.3712069 0.0000000), wk = 0.0312500
k( 49) = ( 0.7500000 0.4330127 0.0000000), wk = 0.0312500
k( 50) = ( 0.7500000 0.5773503 0.0000000), wk = 0.0312500
k( 51) = ( 0.7500000 0.7216878 0.0000000), wk = 0.0312500
k( 52) = ( 0.7500000 0.8660254 0.0000000), wk = 0.0312500
k( 53) = ( 0.7500000 1.0103630 0.0000000), wk = 0.0312500
k( 54) = ( 0.7500000 1.1547005 0.0000000), wk = 0.0312500
k( 55) = ( 0.7500000 1.2990381 0.0000000), wk = 0.0312500
k( 56) = ( 0.7500000 1.4433757 0.0000000), wk = 0.0312500
k( 57) = ( 0.8750000 0.5051815 0.0000000), wk = 0.0312500
k( 58) = ( 0.8750000 0.6495191 0.0000000), wk = 0.0312500
k( 59) = ( 0.8750000 0.7938566 0.0000000), wk = 0.0312500
k( 60) = ( 0.8750000 0.9381942 0.0000000), wk = 0.0312500
k( 61) = ( 0.8750000 1.0825318 0.0000000), wk = 0.0312500
k( 62) = ( 0.8750000 1.2268693 0.0000000), wk = 0.0312500
k( 63) = ( 0.8750000 1.3712069 0.0000000), wk = 0.0312500
k( 64) = ( 0.8750000 1.5155445 0.0000000), wk = 0.0312500

PseudoPot. # 1 for C read from file:
/home/anindya/espresso/pseudo/C_PZ_r.oncvpsp.upf
MD5 check sum: 8244e5e5a9dbe7466d722c8d0ea51c4b
Pseudo is Norm-conserving + core correction, Zval = 4.0
Generated using ONCVPSP code by D. R. Hamann
Using radial grid of 1234 points, 4 beta functions with:
l(1) = 0
l(2) = 0
l(3) = 1
l(4) = 1
EPW : 3.31s CPU 5.84s WALL

EPW : 21.20s CPU 31.67s WALL

No wavefunction gauge setting applied
-------------------------------------------------------------------
Wannierization on 8 x 8 x 1 electronic grid
-------------------------------------------------------------------

Spin CASE ( default = unpolarized )

Initializing Wannier90


Initial Wannier projections

( 0.00000 0.00000 0.50000) : l = 1 mr = 1
( 0.33333 0.66667 0.50000) : l = -2 mr = 1
( 0.33333 0.66667 0.50000) : l = -2 mr = 2
( 0.33333 0.66667 0.50000) : l = -2 mr = 3
( 0.33333 0.66667 0.50000) : l = 1 mr = 1

- Number of bands is ( 20)
- Number of wannier functions is ( 5)
- All guiding functions are given

Reading data about k-point neighbours

- All neighbours are found

AMN
k points = 64 in 4 pools
1 of 16 on ionode
2 of 16 on ionode
3 of 16 on ionode
4 of 16 on ionode
5 of 16 on ionode
6 of 16 on ionode
7 of 16 on ionode
8 of 16 on ionode
9 of 16 on ionode
10 of 16 on ionode
11 of 16 on ionode
12 of 16 on ionode
13 of 16 on ionode
14 of 16 on ionode
15 of 16 on ionode
16 of 16 on ionode

AMN calculated

MMN
k points = 64 in 4 pools
1 of 16 on ionode
2 of 16 on ionode
3 of 16 on ionode
4 of 16 on ionode
5 of 16 on ionode
6 of 16 on ionode
7 of 16 on ionode
8 of 16 on ionode
9 of 16 on ionode
10 of 16 on ionode
11 of 16 on ionode
12 of 16 on ionode
13 of 16 on ionode
14 of 16 on ionode
15 of 16 on ionode
16 of 16 on ionode
MMN calculated

Running Wannier90

Wannier Function centers (cartesian, alat) and spreads (ang):

( -0.24989 0.14436 -10.29855) : 1.25750
( 0.00006 0.86573 10.30157) : 0.60114
( -0.25025 0.43294 -10.30140) : 0.60048
( -0.49980 0.86642 10.30117) : 0.60030
( -0.25033 0.72159 10.29880) : 3.11021

-------------------------------------------------------------------
WANNIER : 238.43s CPU 329.12s WALL ( 1 calls)
-------------------------------------------------------------------

Dipole matrix elements calculated


Calculating kmap and kgmap
Progress kmap: ########################################
Progress kgmap: ########################################
kmaps : 1054.22s CPU 1400.67s WALL ( 1 calls)
Symmetries of bravais lattice: 24
Symmetries of crystal: 24


===================================================================
irreducible q point # 1
===================================================================

Symmetries of small group of q: 24
in addition sym. q -> -q+G:

Number of q in the star = 1
List of q in the star:
1 0.000000000 0.000000000 0.000000000
Imposing acoustic sum rule on the dynamical matrix

q( 1 ) = ( 0.0000000 0.0000000 0.0000000 )


===================================================================
irreducible q point # 2
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.000000000 0.144337567 0.000000000
2 0.000000000 -0.144337567 0.000000000
3 0.125000000 0.072168783 0.000000000
4 -0.125000000 -0.072168783 0.000000000
5 0.125000000 -0.072168783 0.000000000
6 -0.125000000 0.072168783 0.000000000

q( 2 ) = ( 0.0000000 0.1443376 0.0000000 )
q( 3 ) = ( 0.0000000 -0.1443376 0.0000000 )
q( 4 ) = ( 0.1250000 0.0721688 0.0000000 )
q( 5 ) = ( -0.1250000 -0.0721688 0.0000000 )
q( 6 ) = ( 0.1250000 -0.0721688 0.0000000 )
q( 7 ) = ( -0.1250000 0.0721688 0.0000000 )


===================================================================
irreducible q point # 3
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.000000000 0.288675135 0.000000000
2 0.000000000 -0.288675135 0.000000000
3 0.250000000 0.144337568 0.000000000
4 -0.250000000 -0.144337568 0.000000000
5 0.250000000 -0.144337568 0.000000000
6 -0.250000000 0.144337568 0.000000000

q( 8 ) = ( 0.0000000 0.2886751 0.0000000 )
q( 9 ) = ( 0.0000000 -0.2886751 0.0000000 )
q( 10 ) = ( 0.2500000 0.1443376 0.0000000 )
q( 11 ) = ( -0.2500000 -0.1443376 0.0000000 )
q( 12 ) = ( 0.2500000 -0.1443376 0.0000000 )
q( 13 ) = ( -0.2500000 0.1443376 0.0000000 )


===================================================================
irreducible q point # 4
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.000000000 0.433012702 0.000000000
2 0.000000000 -0.433012702 0.000000000
3 0.375000000 0.216506351 0.000000000
4 -0.375000000 -0.216506351 0.000000000
5 0.375000000 -0.216506351 0.000000000
6 -0.375000000 0.216506351 0.000000000

q( 14 ) = ( 0.0000000 0.4330127 0.0000000 )
q( 15 ) = ( 0.0000000 -0.4330127 0.0000000 )
q( 16 ) = ( 0.3750000 0.2165064 0.0000000 )
q( 17 ) = ( -0.3750000 -0.2165064 0.0000000 )
q( 18 ) = ( 0.3750000 -0.2165064 0.0000000 )
q( 19 ) = ( -0.3750000 0.2165064 0.0000000 )


===================================================================
irreducible q point # 5
===================================================================

Symmetries of small group of q: 8
in addition sym. q -> -q+G:

Number of q in the star = 3
List of q in the star:
1 0.000000000 -0.577350269 0.000000000
2 0.500000000 0.288675134 0.000000000
3 -0.500000000 0.288675134 0.000000000

q( 20 ) = ( 0.0000000 -0.5773503 0.0000000 )
q( 21 ) = ( 0.5000000 0.2886751 0.0000000 )
q( 22 ) = ( -0.5000000 0.2886751 0.0000000 )


===================================================================
irreducible q point # 6
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.125000000 0.216506351 0.000000000
2 -0.125000000 -0.216506351 0.000000000
3 0.125000000 -0.216506351 0.000000000
4 0.250000000 -0.000000000 0.000000000
5 -0.250000000 0.000000000 0.000000000
6 -0.125000000 0.216506351 0.000000000

q( 23 ) = ( 0.1250000 0.2165064 0.0000000 )
q( 24 ) = ( -0.1250000 -0.2165064 0.0000000 )
q( 25 ) = ( 0.1250000 -0.2165064 0.0000000 )
q( 26 ) = ( 0.2500000 -0.0000000 0.0000000 )
q( 27 ) = ( -0.2500000 0.0000000 0.0000000 )
q( 28 ) = ( -0.1250000 0.2165064 0.0000000 )


===================================================================
irreducible q point # 7
===================================================================

Symmetries of small group of q: 2

Number of q in the star = 12
List of q in the star:
1 0.125000000 0.360843918 0.000000000
2 0.250000000 0.288675134 0.000000000
3 -0.125000000 -0.360843918 0.000000000
4 0.125000000 -0.360843918 0.000000000
5 -0.250000000 -0.288675134 0.000000000
6 0.375000000 -0.072168784 0.000000000
7 -0.375000000 0.072168784 0.000000000
8 -0.125000000 0.360843918 0.000000000
9 -0.250000000 0.288675134 0.000000000
10 0.375000000 0.072168784 0.000000000
11 -0.375000000 -0.072168784 0.000000000
12 0.250000000 -0.288675134 0.000000000

q( 29 ) = ( 0.1250000 0.3608439 0.0000000 )
q( 30 ) = ( 0.2500000 0.2886751 0.0000000 )
q( 31 ) = ( -0.1250000 -0.3608439 0.0000000 )
q( 32 ) = ( 0.1250000 -0.3608439 0.0000000 )
q( 33 ) = ( -0.2500000 -0.2886751 0.0000000 )
q( 34 ) = ( 0.3750000 -0.0721688 0.0000000 )
q( 35 ) = ( -0.3750000 0.0721688 0.0000000 )
q( 36 ) = ( -0.1250000 0.3608439 0.0000000 )
q( 37 ) = ( -0.2500000 0.2886751 0.0000000 )
q( 38 ) = ( 0.3750000 0.0721688 0.0000000 )
q( 39 ) = ( -0.3750000 -0.0721688 0.0000000 )
q( 40 ) = ( 0.2500000 -0.2886751 0.0000000 )


===================================================================
irreducible q point # 8
===================================================================

Symmetries of small group of q: 2

Number of q in the star = 12
List of q in the star:
1 0.125000000 0.505181486 0.000000000
2 0.375000000 0.360843918 0.000000000
3 -0.125000000 -0.505181486 0.000000000
4 0.125000000 -0.505181486 0.000000000
5 -0.375000000 -0.360843918 0.000000000
6 0.500000000 -0.144337568 0.000000000
7 -0.500000000 0.144337568 0.000000000
8 -0.125000000 0.505181486 0.000000000
9 -0.375000000 0.360843918 0.000000000
10 0.500000000 0.144337568 0.000000000
11 -0.500000000 -0.144337568 0.000000000
12 0.375000000 -0.360843918 0.000000000

q( 41 ) = ( 0.1250000 0.5051815 0.0000000 )
q( 42 ) = ( 0.3750000 0.3608439 0.0000000 )
q( 43 ) = ( -0.1250000 -0.5051815 0.0000000 )
q( 44 ) = ( 0.1250000 -0.5051815 0.0000000 )
q( 45 ) = ( -0.3750000 -0.3608439 0.0000000 )
q( 46 ) = ( 0.5000000 -0.1443376 0.0000000 )
q( 47 ) = ( -0.5000000 0.1443376 0.0000000 )
q( 48 ) = ( -0.1250000 0.5051815 0.0000000 )
q( 49 ) = ( -0.3750000 0.3608439 0.0000000 )
q( 50 ) = ( 0.5000000 0.1443376 0.0000000 )
q( 51 ) = ( -0.5000000 -0.1443376 0.0000000 )
q( 52 ) = ( 0.3750000 -0.3608439 0.0000000 )


===================================================================
irreducible q point # 9
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.250000000 0.433012702 0.000000000
2 -0.250000000 -0.433012702 0.000000000
3 0.250000000 -0.433012702 0.000000000
4 0.500000000 -0.000000000 0.000000000
5 -0.500000000 0.000000000 0.000000000
6 -0.250000000 0.433012702 0.000000000

q( 53 ) = ( 0.2500000 0.4330127 0.0000000 )
q( 54 ) = ( -0.2500000 -0.4330127 0.0000000 )
q( 55 ) = ( 0.2500000 -0.4330127 0.0000000 )
q( 56 ) = ( 0.5000000 -0.0000000 0.0000000 )
q( 57 ) = ( -0.5000000 0.0000000 0.0000000 )
q( 58 ) = ( -0.2500000 0.4330127 0.0000000 )


===================================================================
irreducible q point # 10
===================================================================

Symmetries of small group of q: 4

Number of q in the star = 6
List of q in the star:
1 0.250000000 0.577350269 0.000000000
2 -0.250000000 -0.577350269 0.000000000
3 0.375000000 0.505181485 0.000000000
4 -0.375000000 -0.505181485 0.000000000
5 0.625000000 -0.072168784 0.000000000
6 -0.625000000 0.072168784 0.000000000

q( 59 ) = ( 0.2500000 0.5773503 0.0000000 )
q( 60 ) = ( -0.2500000 -0.5773503 0.0000000 )
q( 61 ) = ( 0.3750000 0.5051815 0.0000000 )
q( 62 ) = ( -0.3750000 -0.5051815 0.0000000 )
q( 63 ) = ( 0.6250000 -0.0721688 0.0000000 )
q( 64 ) = ( -0.6250000 0.0721688 0.0000000 )

Writing epmatq on .epb files


The .epb files have been correctly written


band disentanglement is used: nbndsub = 5

Writing Hamiltonian, Dynamical matrix and EP vertex in Wann rep to file


Reading Hamiltonian, Dynamical matrix and EP vertex in Wann rep from file


Finished reading Wann rep data from file

===================================================================
Memory usage: VmHWM = 504Mb
VmPeak = 980Mb
===================================================================

Using uniform q-mesh: 32 32 1
Size of q point mesh for interpolation: 1024
Using uniform k-mesh: 32 32 1
Size of k point mesh for interpolation: 2048
Max number of k points per pool: 512

Fermi energy coarse grid = -3.924488 eV

Fermi energy is calculated from the fine k-mesh: Ef = -3.835342 eV

===================================================================

ibndmin = 3 ebndmin = -0.649
ibndmax = 5 ebndmax = 0.079


Number of ep-matrix elements per pool : 13824 ~= 108.00 Kb (@ 8 bytes/ DP)

===================================================================
Phonon (Imaginary) Self-Energy in the Migdal Approximation
===================================================================


Fermi Surface thickness = 5.000000 eV

Golden Rule strictly enforced with T = 0.025852 eV
Gaussian Broadening: 0.025000 eV, ngauss= 1
DOS = -0.000000 states/spin/eV/Unit Cell at Ef= -3.835342 eV

ismear = 1 iq = 1 coord.: 0.00000 0.00000 0.00000 wt: 0.00098
-------------------------------------------------------------------
lambda___( 1 )= 0.000000 gamma___= 0.000000 meV omega= 0.0058 meV
lambda_tr( 1 )= 0.000000 gamma_tr= 0.000000 meV omega= 0.0058 meV
lambda___( 2 )= 0.000000 gamma___= 0.000000 meV omega= 0.0125 meV
lambda_tr( 2 )= 0.000000 gamma_tr= 0.000000 meV omega= 0.0125 meV
lambda___( 3 )= 0.000000 gamma___= 0.000000 meV omega= 0.0148 meV
lambda_tr( 3 )= 0.000000 gamma_tr= 0.000000 meV omega= 0.0148 meV
lambda___( 4 )=*************** gamma___=13178664.551991 meV omega= 111.0951 meV
lambda_tr( 4 )=*************** gamma_tr=*************** meV omega= 111.0951 meV
lambda___( 5 )=*************** gamma___=-5433074.204840 meV omega= 197.6488 meV
lambda_tr( 5 )=*************** gamma_tr=*************** meV omega= 197.6488 meV
lambda___( 6 )=*************** gamma___=45800666.390756 meV omega= 197.6488 meV
lambda_tr( 6 )=*************** gamma_tr=*************** meV omega= 197.6488 meV
lambda___( tot )=***************
lambda_tr( tot )=***************
-------------------------------------------------------------------

ismear = 1 iq = 2 coord.: 0.00000 0.03125 0.00000 wt: 0.00098
-------------------------------------------------------------------
lambda___( 1 )=*************** gamma___=*************** meV omega= 0.9967 meV
lambda_tr( 1 )=*************** gamma_tr=*************** meV omega= 0.9967 meV
lambda___( 2 )=*************** gamma___=*************** meV omega= 8.3826 meV
lambda_tr( 2 )=*************** gamma_tr=*************** meV omega= 8.3826 meV
lambda___( 3 )=*************** gamma___=*************** meV omega= 13.1905 meV
lambda_tr( 3 )=*************** gamma_tr=*************** meV omega= 13.1905 meV
lambda___( 4 )=*************** gamma___=*************** meV omega= 110.9951 meV
lambda_tr( 4 )=*************** gamma_tr=*************** meV omega= 110.9951 meV
lambda___( 5 )=*************** gamma___=*************** meV omega= 196.9914 meV
lambda_tr( 5 )=*************** gamma_tr=*************** meV omega= 196.9914 meV
lambda___( 6 )=*************** gamma___=*************** meV omega= 197.8079 meV
lambda_tr( 6 )=*************** gamma_tr=*************** meV omega= 197.8079 meV
lambda___( tot )=***************
lambda_tr( tot )=***************
-------------------------------------------------------------------


Number of (k,k+q) pairs on the Fermi surface: 816 out of 1024


ismear = 1 iq = 3 coord.: 0.00000 0.06250 0.00000 wt: 0.00098
-------------------------------------------------------------------
lambda___( 1 )=*************** gamma___=*************** meV omega= 2.2704 meV
lambda_tr( 1 )=*************** gamma_tr=*************** meV omega= 2.2704 meV
lambda___( 2 )=*************** gamma___=*************** meV omega= 16.6076 meV
lambda_tr( 2 )=*************** gamma_tr=*************** meV omega= 16.6076 meV
lambda___( 3 )=*************** gamma___=*************** meV omega= 26.2133 meV
lambda_tr( 3 )=*************** gamma_tr=*************** meV omega= 26.2133 meV
lambda___( 4 )=*************** gamma___=*************** meV omega= 110.6942 meV
lambda_tr( 4 )=*************** gamma_tr=*************** meV omega= 110.6942 meV
lambda___( 5 )=*************** gamma___=*************** meV omega= 195.2331 meV
lambda_tr( 5 )=*************** gamma_tr=*************** meV omega= 195.2331 meV
lambda___( 6 )=*************** gamma___=*************** meV omega= 198.2522 meV
lambda_tr( 6 )=*************** gamma_tr=*************** meV omega= 198.2522 meV
lambda___( tot )=***************
lambda_tr( tot )=***************
-------------------------------------------------------------------


Number of (k,k+q) pairs on the Fermi surface: 776 out of 1024


ismear = 1 iq = 4 coord.: 0.00000 0.09375 0.00000 wt: 0.00098
-------------------------------------------------------------------
lambda___( 1 )=*************** gamma___=*************** meV omega= 3.9866 meV
lambda_tr( 1 )=*************** gamma_tr=*************** meV omega= 3.9866 meV
lambda___( 2 )=*************** gamma___=*************** meV omega= 24.5489 meV
lambda_tr( 2 )=*************** gamma_tr=*************** meV omega= 24.5489 meV
lambda___( 3 )=*************** gamma___=*************** meV omega= 38.9565 meV
lambda_tr( 3 )=*************** gamma_tr=*************** meV omega= 38.9565 meV
lambda___( 4 )=*************** gamma___=*************** meV omega= 110.1880 meV
lambda_tr( 4 )=*************** gamma_tr=*************** meV omega= 110.1880 meV
lambda___( 5 )=*************** gamma___=*************** meV omega= 192.8971 meV
lambda_tr( 5 )=*************** gamma_tr=*************** meV omega= 192.8971 meV
lambda___( 6 )=*************** gamma___=*************** meV omega= 198.8726 meV
lambda_tr( 6 )=*************** gamma_tr=*************** meV omega= 198.8726 meV
lambda___( tot )=***************
lambda_tr( tot )=***************
-------------------------------------------------------------------

.
.
.
.
.
.
===================================================================
Memory usage: VmHWM = 504Mb
VmPeak = 980Mb
===================================================================


===================================================================
Eliashberg Spectral Function in the Migdal Approximation
===================================================================

lambda : ************
lambda_tr : ************

Estimated Allen-Dynes Tc

logavg = 0.0004605 l_a2F = ************
mu = 0.10 Tc = 19.991165055928 K
mu = 0.12 Tc = 19.696420670787 K
mu = 0.14 Tc = 19.398195490821 K
mu = 0.16 Tc = 19.096462829571 K
mu = 0.18 Tc = 18.791198191394 K
mu = 0.20 Tc = 18.482379544293 K
a2F : 0.40s CPU 0.59s WALL ( 1 calls)

Unfolding on the coarse grid
elphon_wrap : 26333.74s CPU 35062.00s WALL ( 1 calls)

INITIALIZATION:

set_drhoc : 483.62s CPU 637.99s WALL ( 65 calls)
init_vloc : 25.05s CPU 33.27s WALL ( 66 calls)
init_us_1 : 1.19s CPU 1.43s WALL ( 66 calls)


Electron-Phonon interpolation
ephwann : 216.66s CPU 290.45s WALL ( 1 calls)
ep-interp : 199.90s CPU 267.81s WALL ( 1024 calls)
PH SELF-ENER : 0.68s CPU 0.65s WALL ( 1024 calls)

Ham: step 1 : 0.00s CPU 0.00s WALL ( 1 calls)
Ham: step 2 : 0.33s CPU 0.33s WALL ( 1 calls)
ep: step 1 : 0.03s CPU 0.03s WALL ( 384 calls)
ep: step 2 : 9.37s CPU 12.69s WALL ( 384 calls)
DynW2B : 0.06s CPU 0.05s WALL ( 1024 calls)
HamW2B : 9.05s CPU 14.11s WALL ( 524800 calls)
ephW2Bp : 95.15s CPU 128.26s WALL ( 1024 calls)


Total program execution
EPW : 7h26m CPU 9h55m WALL


Please consider citing:
S. Ponce, E. R. Margine, C. Verdi and F. Giustino, Comput. Phys. Commun. 209, 116 (2016)

Thanks and regards,
Anindya Bose
Research Fellow,
IIIT Allahabad

Dear Experts,
I have enclosed a copy of my wannier band structure in this link : https://ibb.co/buwCrK , which shows a band gap of few eVs in graphene.Can this be the reason for wrong a2f result.I will be waiting for a valuable suggestion.

Thanks and regards,
Anindya Bose

Hi!

I would say that, although the spreads are low, you wannierization didn't went well.
300 for num_iter and dis_num_iter seem too smal to me.
Besides the gap at Dirac point there are number of strange looking regions on band structure,
which would be seen if you compare your W90 band structure with the DFT one.

Also, did your DFT calculation went well? Try increasing the accuracy: 8x8 kp may not be enough for
material with Dirac cones, encut may also be worth increasing.

Best,
Andrei

Dear Sir,
Please have a look on my pw band structure link: https://ibb.co/g5bawK .It looks absolutely fine.Still I am not able to get correct wannier band structure and a2f.Please help me to resolve this issue.

Thanks and regards,
Anindya Bose

Dear Experts,
Please suggest me a way to correct the wannierization,
1.Do I need to change my proj(1)?
2.I took dis_win_max and min as per DFT window size, am I wrong in this?
3.I took dis_froz_max as per my fermi level value, am I wrong in this?
4.I took dis_froz_min=dis_win_min , am I wrong in this?
5.Is there any further correction which I can make to correct my wannierization and the output result?
Please suggest me.

Thanks and regards,
Anindya Bose

Hi Anindya,

Your lambdas and a2f are wrong because 'DOS = -0.000000' at the Fermi level, and that factor goes at the denominator in the formulas.
Looking at your input file, you used an 8x8 initial k grid, but for graphene you probably need a denser one.

Best,
Carla

Dear Carla,
How can I resolve this issue? Should I make the nscf calculation with dense grid like 16x16x1 or more.Should I do the phonon calculation with dense grid or not?

Thanks and regards,
Anindya Bose

Hi Anindya,

In addition to Carla's comments, in case you have not seen this, the following website (http://osuginoissp.wixsite.com/mysite/2-2-1-graphene) uses QE to do the DFT and Wannier band structures of graphene. Maybe their settings for Wannier windows and projections will answer your Wannier-related questions.

Cheers,

Vahid

Vahid Askarpour
Department of Physics and Atmospheric Science
Dalhousie University,
Halifax, NS, Canada

Thank you for the useful link Vahid.
Anindya, the phonons are unrelated to the wannierization of the band structure. You might need to redo the phonon calculation on a denser grid, but that would be in order to better converge your electron-phonon quantities. For now you can focus on obtaining a satisfactory wannierization of the electronic part.

Best,
Carla

Dear Dr Carla and Mr Vahid,
Thank you so much for your valuable suggestions.I am having one more query regarding the wannierization.Suppose in my DFT nscf calculation I have taken 20 bands and which is lying in the energy window between -25 to +15 (eV) and if I include 5 bands for wannier or epw calculation then should I give the same window size from -25 to +15 using dis_win_min,dis_win_max or I have to choose a particular upper level of dis_win_max within that exact 5 bands are coming as per DFT band diagram. dis_froz_max will always be the fermi level value? Rectify me.

Thanks and regards,
Anindya Bose