EPW Forum

Dear EPW-developers,

While using EPW with QE-6.6 (compiled with Intel 17), I am facing the below error:
"Error in routine readwfc (20): error opening wfc file"
From previous posts, I haven't find any fix for this error. Could you please suggest on how to fix this error.

Warm regards,
Prasad
JNCASR, Bangalore.

Dear Prasad:

Are there *.wfc* files in your working directory?

Sincerely,

H. Lee

Dear Lee,

Yes, .wfc files are in the working directory. The run completing well the AMN, MMN calculations and till the end of Wannier part. It is crashing at:

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

Symmetries of small group of q: 12
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 )

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine readwfc (20):
error opening wfc file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...

Regards,
Prasad
JNCASR, Bangalore

Dear Prasad:

I would like to look at your all inputs (scf.in, ph.in, nscf.in, and epw.in) and epw.out.
I assume that you are using the same number of cores as the number of pools in your EPW runs.

Sincerely,

H. Lee

Dear Lee,

scf.in:
&CONTROL
calculation='scf',
outdir='./',
prefix='xx',
pseudo_dir='../../../',
wf_collect=.true.,
verbosity='high',
/

&SYSTEM
ibrav=0,
celldm(1)=15.325677767d0,
nat=16,
ntyp=3,
ecutwfc=50,
occupations='smearing',
smearing='fd',
degauss=0.003d0,
/

&ELECTRONS
conv_thr=1d-08,
mixing_beta=0.2d0,
/
ATOMIC_SPECIES
....

CELL_PARAMETERS (alat= 15.32567777)
...

ATOMIC_POSITIONS (crystal)
....
...

K_POINTS {automatic}
6 6 6 0 0 0

ph.in:
&inputph
tr2_ph=1.0d-14,
prefix='xx',
outdir='./tmp',
fildyn='xx.dyn',
fildvscf='dvscf',
ldisp=.true.,
recover=.true.,
nq1=2, nq2=2, nq3=2
/

nscf.in:
&CONTROL
calculation='nscf',
outdir='./',
prefix='xx',
pseudo_dir='../../../',
! wf_collect=.true.,
verbosity='high',
/

&SYSTEM
ibrav=0,
celldm(1)=15.325677767d0,
nat=16,
ntyp=3,
ecutwfc=50,
occupations='smearing',
smearing='fd',
degauss=0.003d0,
nbnd=75
/

&ELECTRONS
conv_thr=1d-08,
mixing_beta=0.2d0,
/

ATOMIC_SPECIES
....

CELL_PARAMETERS (alat= 15.32567777)
...

ATOMIC_POSITIONS (crystal)
....
...

K_POINTS crystal
1728
0.00000000 0.00000000 0.00000000 5.787037e-04
0.00000000 0.00000000 0.08333333 5.787037e-04
0.00000000 0.00000000 0.16666667 5.787037e-04
....

epw.in:
&inputepw
prefix = 'xx',
amass(1) = xx
amass(2) = xx
amass(3) = xx
outdir = './'
dvscf_dir = '../epc1/save'

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

epwwrite = .true.
epwread = .false.

nbndsub = 60
!nbndskip = 5

wannierize = .true.
num_iter = 500

dis_win_max = 12d0
dis_win_min = -7.5d0
dis_froz_min= 7d0
dis_froz_max= 10d0
proj(1) = 'random'

wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = 'G 0.00 0.00 0.00 X 0.50 0.00 0.50'
wdata(4) = 'X 0.50 0.00 0.50 W 0.50 0.25 0.75'
wdata(5) = 'W 0.50 0.25 0.75 K 0.375 0.375 0.75'
wdata(6) = 'K 0.375 0.375 0.75 G 0.00 0.00 0.00'
wdata(7) = 'G 0.00 0.00 0.00 L 0.50 0.50 0.50'
wdata(8) = 'L 0.50 0.50 0.50 U 0.625 0.25 0.625'
wdata(9) = 'end kpoint_path'
wdata(10) = 'bands_num_points = 50'

iverbosity = 0

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

fsthick = 1 ! eV
degaussw = 0.1 ! eV

nkf1 = 36
nkf2 = 36
nkf3 = 36
nqf1 = 12
nqf2 = 12
nqf3 = 12

nk1 = 12
nk2 = 12
nk3 = 12
nq1 = 2
nq2 = 2
nq3 = 2
/

epw.out: [lines at the end]
-------------------------------------------------------------------
WANNIER : 6461.77s CPU 7120.97s WALL ( 1 calls)
-------------------------------------------------------------------

Calculating kgmap

Progress kgmap: ########################################
kmaps : 0.35s CPU 2.03s WALL ( 1 calls)
Symmetries of Bravais lattice: 12
Symmetries of crystal: 12


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

Symmetries of small group of q: 12
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: 12
in addition sym. q -> -q+G:

Number of q in the star = 1
List of q in the star:
1 0.000000000 0.000000000 -0.622108626

q( 2 ) = ( 0.0000000 0.0000000 -0.6221086 )


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

Symmetries of small group of q: 4
in addition sym. q -> -q+G:

Number of q in the star = 3
List of q in the star:
1 0.000000000 -0.586529620 0.207369542
2 0.507949552 -0.293264810 -0.207369542
3 -0.507949552 -0.293264810 -0.207369542

q( 3 ) = ( 0.0000000 -0.5865296 0.2073695 )
q( 4 ) = ( 0.5079496 -0.2932648 -0.2073695 )

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine readwfc (20):
error opening wfc file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...

I hope these are useful to analyse, please let me know if you need them in more detail I can send them in attachment,
Regards,
Prasad

Dear Prasad:

It looks to me that your inputs don't have something problematic.

I would just ask you the following two things:
(1) In your first post, the error occurred after iq = 1, but in your last post, it occurred after iq = 4. Does the error of readwfc occur at the different steps depending on the runs?
(2) Could you check whether the number of k points is "1728" in your nscf.out; please search for "number of k points=" in nscf.out.
(3) I want to look at your job script for the EPW run.

Sincerely,

H. Lee

Dear Lee,

Yes, with 96 processors(for scf, nscf & epw runs) it crashed at iq=1, with 48 procs it crashed at iq=4.
dvscf files are generated by the ph run with much larger no. of procs.

Yes, number of k points=1728 in nscf.out [12x12x12]

submit.sh:
module load compilers/intel2017/composer_xe_2017/default
export bin=$(cd /home/prasad/qe-6.6/bin; pwd)

mpirun --hostfile noda -np 48 $bin/pw.x -npool 48 -in pw.in > pw.out
mpirun --hostfile noda -np 48 $bin/pw.x -npool 48 -in nscf.in > nscf.out
mpirun --hostfile noda -np 48 $bin/epw.x -npool 48 -in epw.in > epw.out

Regards,
Prasad

Dear Prasad:

I still don't know what happens in your calculations; it looks to me that there is nothing problematic and it is strange to me that the error occurs at the different steps depending on the number of cores used.

I can't give you the clear answer, but I would just suggest you to run the test-suite for EPW by issuing "make run-tests-epw-parallel" in q-e/test-suite or print out the number of ios by chaning "IF (ios /= 0) CALL errore('readwfc', 'error opening wfc file', iuwfc)" with "IF (ios /= 0) CALL errore('readwfc', 'error opening wfc file', ios)" in io_epw.f90 in EPW/src (as you know well, you need to recompile the code).

Added after the first post:
I found the similar issue in the old posts:
Please check the posts at viewtopic.php?f=6&t=763&p=2424&hilit=readwfc#p2424 or viewtopic.php?f=6&t=752&p=2370&hilit=readwfc#p2370 .

Sincerely,

H. Lee

Dear Lee,

Thanks for your help. When I issue "make run-tests-epw-parallel", all tests related to epw*.in are failed, and showing the below error:

Error in routine readwfc (20):
error opening wfc file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...
epw_metal - epw1.in (arg(s): 3): **FAILED**.
Different sets of data extracted from benchmark and test.
Data only in benchmark: rsig, gamma, lam, e2, lam_tot, dos1, isig, z1, lam_tr, omega, l_a2f, logavg, lambda_tr, efm.
More data in benchmark than in test: q1.

This hints that my qe installation is not working with EPW. Please suggest what could be the probable reason.

Thanks in advance.

Regards,
Prasad

Dear Prasad:

Added after the first post:
I found the similar issue in the old posts:
Please check the posts at viewtopic.php?f=6&t=763&p=2424&hilit=readwfc#p2424 or viewtopic.php?f=6&t=752&p=2370&hilit=readwfc#p2370 .

As you can see from the messages above, it seems that there is an issue with some sub-versions of Intel compiler v17.
Please try the different (higher) versions of Intel compiler or the gnu compiler.

Sincerely,

H. Lee