EPW calculation for mobility

[Maitryj]

Hello,

I want to run a calculation for finding phonon limited mobility of MgTe inclusion of electron-phonon coupling. scf and phonon calculations done successfully but epw1 calculation shows following error. I am attaching scf, ph and epw input file here.

Please guide me how to correct my epw1.in file.

Thanks,
Maitryj.

Title line not specified: using 'default'.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine epw_readin (5010):
reading input_epw namelist
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...

#scf.in
&control
calculation='scf',
prefix='MgTe',
pseudo_dir = './',
outdir='./out',
tstress = .true.
tprnfor = .true.
restart_mode = 'from_scratch',
verbosity = 'high',
wf_collect = .true.
/
&system
ibrav = 2,
A = 5.979,
nat = 2,
ntyp = 2,
ecutwfc = 90,
occupations='smearing'
smearing='gaussian'
degauss=0.001
/
&electrons
diagonalization='david'
mixing_beta=0.7,
conv_thr = 1.0d-10,
diago_full_acc = .true.
/


ATOMIC_SPECIES
Mg 24.305 Mg.UPF
Te 121.90304 Te.UPF

ATOMIC_POSITIONS (crystal)
Mg 0.000000000 0.000000000 0.000000000
Te 0.500000000 0.500000000 0.500000000

K_POINTS automatic
12 12 12 0 0 0

#ph.in
&inputph
recover = .true.,
tr2_ph=1.0d-17,
prefix='MgTe',
outdir='./out',
fildyn='MgTe.dyn',
fildvscf='dvscf'
ldisp=.true.,
!epsil=.true.,
nq1 = 4,
nq2 = 4,
nq3 = 4
/

#epw1.in

&inputepw
prefix = 'MgTe'
amass(1) = 24.305,
amass(2) = 121.90304,
outdir = './out',
elph = .true.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.

! lpolar = .true. ! polar material
vme = 'wannier'
use_ws = .false. ! Gamma centred Wigner-Seitz cell
nbndsub = 4,
etf_mem = 1,
wannierize = .true.
num_iter = 50000
iprint = 2
dis_win_max = 12.0,
dis_win_min = -1.0,
proj(1) = 'Te:5d'

wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = ' G 0.000 0.000 0.000 X 0.500 0.000 0.500'
wdata(4) = ' X 0.500 0.000 0.500 U 0.625 0.250 0.625'
wdata(5) = ' K 0.375 0.375 0.750 G 0.000 0.000 0.000 '
wdata(6) = ' G 0.000 0.000 0.000 L 0.500 0.500 0.500 '
wdata(7) = ' L 0.500 0.500 0.500 W 0.500 0.250 0.750 '
wdata(8) = ' W 0.500 0.250 0.750 X 0.500 0.000 0.500 '
wdata(9) = 'end kpoint_path'
wdata(10) = 'bands_plot_format = gnuplot'
wdata(11) = 'guiding_centres = .true.'
wdata(12) = 'dis_num_iter = 5000'
wdata(13) = 'num_print_cycles = 10'
wdata(12) = 'dis_mix_ratio = 1.0'

wdata(14) = 'conv_tol = 1E-12'
wdata(15) = 'conv_window = 4'
wdata(16) = 'use_ws_distance = T'
elecselfen = .false.
phonselfen = .false.
a2f = .false.
fsthick = 100
nstemp = 1
temps = 1
degaussw = 0.001
dvscf_dir = '../out/MgTe.save'
band_plot = .true.
filkf = './MgTe.txt'
filqf = './MgTe.txt'
nk1 = 12
nk2 = 12
nk3 = 12
nq1 = 4
nq2 = 4
nq3 = 4
/

[hpaudya1]

Hi Mytryj,

It looks like you have a problem in a specific input flag "vme". Your input works fine for the qe6.8 (EPWv5.4) version, but with the previous versions it does not. I am not sure which version of the code are you using, please have a look at the following for more detail.

https://gitlab.com/QEF/q-e/-/blob/devel ... n.f90#L360

Best,
Hari

[Maitryj]

Hello,

Can anyone explain about the quadrupole.fmt file ? Is it needed for calculation phonon limited mobility including electro-phonon coupling ( in epw1.in file)? Which are the ways to conduct file ?

[hlee]

Dear Maitryj:

I think that currently the support for quadrupole in EPW v5.4 is partial and its use is not easy in the sense that the quadrupole tensor contained in quadrupole.fmt should be obtained by (1) Abinit (https://www.abinit.org/) calculations or (2) fitting the electron-phonon matrix elements from EPW to those from direct DFPT calculations.

If there is no quadrupole.fmt, the quadrupole correction is not included as in the previous versions of EPW.

Sincerely,

H. Lee