EPW Forum

Dear developers,

I want to calculate the electron self energy. However, it always appeared error of too many g-vector. I used a smaller energy cutoff and it worked. However, I wonder if there is any other method to fix up the problem, since I do not want to sacrifice the precision. Here are my input files.

scf.in:
&CONTROL
calculation='scf'
restart_mode='from_scratch'
outdir='./'
pseudo_dir='/work/k0116/k011622/pseudo'
prefix= 'MoO3'
etot_conv_thr=1.0D-09
forc_conv_thr=1.0D-09
wf_collect=.true.
tstress=.true.
tprnfor=.true.
/
&SYSTEM
ibrav=8
celldm(1)=6.954407601
celldm(2)=1.069190824
celldm(3)=7.625614123
nat=8
ntyp=2
ecutwfc=90.0
nbnd =60
nspin=1
nr1=40
nr2=44
nr3=300
/
&ELECTRONS
conv_thr=1.0e-09
mixing_beta=0.4
/
ATOMIC_SPECIES
Mo 95.94 Mo_ONCV_PBE-1.0.upf
O 15.999 O_ONCV_PBE-1.0.upf
ATOMIC_POSITIONS crystal
Mo 0.750000000 0.571487762 -0.054029957
Mo 0.250000000 0.428512280 0.054029957
O 0.250000000 0.497852060 -0.03412717
O 0.750000000 0.502148112 0.034127155
O 0.750000000 0.015453203 -0.046343122
O 0.250000000 0.984546858 0.046343102
O 0.750000000 0.531000473 -0.113557105
O 0.250000000 0.468999251 0.113557105
K_POINTS automatic
8 8 1 0 0 0


nscf.in:
&CONTROL
calculation='nscf'
restart_mode='from_scratch'
outdir='./'
pseudo_dir='/work/k0116/k011622/pseudo'
prefix= 'MoO3'
etot_conv_thr=1.0D-09
forc_conv_thr=1.0D-09
wf_collect=.true.
tstress=.true.
tprnfor=.true.
/
&SYSTEM
ibrav=8
celldm(1)=6.954407601
celldm(2)=1.069190824
celldm(3)=7.625614123
nat=8
ntyp=2
ecutwfc=90.0
nbnd =60
nspin=1
nr1=40
nr2=44
nr3=300
/
&ELECTRONS
conv_thr=1.0e-09
mixing_beta=0.4
/
ATOMIC_SPECIES
Mo 95.94 Mo_ONCV_PBE-1.0.upf
O 15.999 O_ONCV_PBE-1.0.upf
ATOMIC_POSITIONS crystal
Mo 0.750000000 0.571487762 -0.054029957
Mo 0.250000000 0.428512280 0.054029957
O 0.250000000 0.497852060 -0.03412717
O 0.750000000 0.502148112 0.034127155
O 0.750000000 0.015453203 -0.046343122
O 0.250000000 0.984546858 0.046343102
O 0.750000000 0.531000473 -0.113557105
O 0.250000000 0.468999251 0.113557105
K_POINTS crystal
64
0 0 0 0.015625
0 0.125 0 0.015625
0 0.25 0 0.015625
0 0.375 0 0.015625
0 0.5 0 0.015625
0 0.625 0 0.015625
0 0.75 0 0.015625
0 0.875 0 0.015625
0.125 0 0 0.015625
0.125 0.125 0 0.015625
0.125 0.25 0 0.015625
0.125 0.375 0 0.015625
0.125 0.5 0 0.015625
0.125 0.625 0 0.015625
0.125 0.75 0 0.015625
0.125 0.875 0 0.015625
0.25 0 0 0.015625
0.25 0.125 0 0.015625
0.25 0.25 0 0.015625
0.25 0.375 0 0.015625
0.25 0.5 0 0.015625
0.25 0.625 0 0.015625
0.25 0.75 0 0.015625
0.25 0.875 0 0.015625
0.375 0 0 0.015625
0.375 0.125 0 0.015625
0.375 0.25 0 0.015625
0.375 0.375 0 0.015625
0.375 0.5 0 0.015625
0.375 0.625 0 0.015625
0.375 0.75 0 0.015625
0.375 0.875 0 0.015625
0.5 0 0 0.015625
0.5 0.125 0 0.015625
0.5 0.25 0 0.015625
0.5 0.375 0 0.015625
0.5 0.5 0 0.015625
0.5 0.625 0 0.015625
0.5 0.75 0 0.015625
0.5 0.875 0 0.015625
0.625 0 0 0.015625
0.625 0.125 0 0.015625
0.625 0.25 0 0.015625
0.625 0.375 0 0.015625
0.625 0.5 0 0.015625
0.625 0.625 0 0.015625
0.625 0.75 0 0.015625
0.625 0.875 0 0.015625
0.75 0 0 0.015625
0.75 0.125 0 0.015625
0.75 0.25 0 0.015625
0.75 0.375 0 0.015625
0.75 0.5 0 0.015625
0.75 0.625 0 0.015625
0.75 0.75 0 0.015625
0.75 0.875 0 0.015625
0.875 0 0 0.015625
0.875 0.125 0 0.015625
0.875 0.25 0 0.015625
0.875 0.375 0 0.015625
0.875 0.5 0 0.015625
0.875 0.625 0 0.015625
0.875 0.75 0 0.015625
0.875 0.875 0 0.015625

epw.in
--
&inputepw
prefix= 'MoO3'
amass(1)= 95.94
amass(2)= 15.999
outdir='./'
iverbosity =0
elph = .true.
epbwrite = .true.
epbread = .false.
lpolar = .true.
epwwrite = .true.
epwread = .false.
nbndsub = 28
nbndskip = 0
wannierize = .true.
iprint =2

!wannier control tags
num_iter = 1000
iprint = 2
dis_win_min= -11.73
dis_win_max= 4.775
dis_froz_min = -11.73
dis_froz_max = -0.165

proj(1) = 'Mo:d'
proj(2) = 'O:p'

wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = 'G 0.000 0.000 0.000 X 0.500 0.000 0.000'
wdata(4) = 'X 0.500 0.000 0.000 S 0.500 0.500 0.000'
wdata(5) = 'S 0.500 0.500 0.000 Y 0.000 0.500 0.000'
wdata(6) = 'Y 0.000 0.500 0.000 G 0.000 0.000 0.000'
wdata(7) ='end kpoint_path'
wdata(8) ='bands_plot_format = gnuplot'
wdata(9) ='dis_num_iter = 1000 ' !set maximum iteration number

!epc calculation control tags
elecselfen = .true.
phonselfen = .false.
a2f = .false.
fsthick = 10.0 ! eV
eptemp = 100 ! K
degaussw = 0.02 ! eV
efermi_read = .true.
fermi_energy = -4.7328 !K valence top
dvscf_dir = '../save'

mp_mesh_k=.true.

!Wannier fine mesh
nkf1 = 80 !replace by appropriate number
nkf2 = 80 !replace by appropriate number
nkf3 = 1 !replace by appropriate number
!if you want to calculate on specific path, please use
!filqf = 'path'
nqf1 = 80 !replace by appropriate number
nqf2 = 80 !replace by appropriate number
nqf3 = 1 !replace by appropriate number

!original mesh
nk1 =8
nk2 =8
nk3 =1
nq1 =8
nq2 =8
nq3 =1
/
25 cartesian
0.000000000000000E+00 0.000000000000000E+00 0.000000000000000E+00
0.000000000000000E+00 0.116910842474645E+00 0.000000000000000E+00
0.000000000000000E+00 0.233821684949290E+00 0.000000000000000E+00
0.000000000000000E+00 0.350732527423935E+00 0.000000000000000E+00
0.000000000000000E+00 -0.467643369898580E+00 0.000000000000000E+00
0.125000000000000E+00 0.000000000000000E+00 0.000000000000000E+00
0.125000000000000E+00 0.116910842474645E+00 0.000000000000000E+00
0.125000000000000E+00 0.233821684949290E+00 0.000000000000000E+00
0.125000000000000E+00 0.350732527423935E+00 0.000000000000000E+00
0.125000000000000E+00 -0.467643369898580E+00 0.000000000000000E+00
0.250000000000000E+00 0.000000000000000E+00 0.000000000000000E+00
0.250000000000000E+00 0.116910842474645E+00 0.000000000000000E+00
0.250000000000000E+00 0.233821684949290E+00 0.000000000000000E+00
0.250000000000000E+00 0.350732527423935E+00 0.000000000000000E+00
0.250000000000000E+00 -0.467643369898580E+00 0.000000000000000E+00
0.375000000000000E+00 0.000000000000000E+00 0.000000000000000E+00
0.375000000000000E+00 0.116910842474645E+00 0.000000000000000E+00
0.375000000000000E+00 0.233821684949290E+00 0.000000000000000E+00
0.375000000000000E+00 0.350732527423935E+00 0.000000000000000E+00
0.375000000000000E+00 -0.467643369898580E+00 0.000000000000000E+00
-0.500000000000000E+00 0.000000000000000E+00 0.000000000000000E+00
-0.500000000000000E+00 0.116910842474645E+00 0.000000000000000E+00
-0.500000000000000E+00 0.233821684949290E+00 0.000000000000000E+00
-0.500000000000000E+00 0.350732527423935E+00 0.000000000000000E+00
-0.500000000000000E+00 -0.467643369898580E+00 0.000000000000000E+00

And the error is showed:

-------------------------------------------------------------------
WANNIER : 85.46s CPU 96.26s WALL ( 1 calls)
-------------------------------------------------------------------

Dipole matrix elements calculated


Calculating kmap and kgmap

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine ggen (312142):
too many g-vectors
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...


It finished wannier calculation but error happened when calculating kmap and kgmap.
If anyone can help me, I would appreciate it very much! Thank you.

Best wishes,
CHOU

Dear CHOU,

This usually happens when you do not have the same ecut for the phonon calculation (producing the dvscf) and for the scf and nscf for the epw calculations.

Best wishes,
Samuel

Dear Samuel,

Thank you for your reply. I used the same ecut for phonon calculation and for the scf and nscf in the epw calculation. But the error happened. For example, I set 90 Ry for phonon calculation, and 90 Ry for epw calculation, but it failed. I changed to 80 Ry for epw while keeping ecut to be 90 Ry for phonon part, it still failed. When I changed to 70 Ry for epw while keeping 90 Ry for phonon, it worked. Therefore, do you have any other solutions for this problem?
Thank you very much.

Best wishes,
CHOU

Hello,

This is indeed quite surprising. Maybe try removing the
"nspin=1
nr1=40
nr2=44
nr3=300"
variable from your scf and nscf.in inputs ?
Why not let the code decide the fft grid ?

Also, can you try one of the example from q-e/test-suite/epw* tests ?
Do they work or you also get this issue ?

If they work, try removing as many input variables that are not needed from your input to see if this help.

Best wishes,
Samuel

Dear Samuel,

Sorry for my late reply.
I removed the FFT setting from scf and nscf. It worked now.
The reason I set FFT mesh by myself is because "note: 2 additional sym.ops. were found but ignored?their fractional translations are incommensurate with FFT grid) " appeared in my output file. I want to find all symmetry.
Although it is not related to EPW, could you give me some suggestion towards the problem? Is just ignoring it proper for calculation?

Best wishes,
CHOU

Dear CHOU,

Since the FFT real space grid is determined as follow:



You can modify it by changing your ecut or your lattice parameters.

Just modify it until you find a grid that is commensurate.

Best,
Samuel

Dear Samuel,

Thank you for your advice.

Best wishes,
CHOU