EPW Forum

Hi,

I am trying to evaluate electron and hole mobility separately keeping int_mob = .false.
Hole mobility is evaluated without error whereas the electron mobility job crashes with a segmentation fault. If the option int_mob=.true. then the job completes without error. Basic checks for interpolation of bandstructure and phonon dispersion are correct.

The segmentation fault message is:
=====================================
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image PC Routine Line Source
epw.x 0000000020BCDF54 Unknown Unknown Unknown
libpthread-2.22.s 00002AAAAFE73C10 Unknown Unknown Unknown
epw.x 0000000020173AEB transport_mp_scat 348 transport.f90
epw.x 000000002005D449 ephwann_shuffle_ 1464 ephwann_shuffle.f90
epw.x 000000002003C36F elphon_shuffle_wr 939 elphon_shuffle_wrap.f90
epw.x 00000000200121AF MAIN__ 145 epw.f90
epw.x 000000002001155E Unknown Unknown Unknown
libc-2.22.so 00002AAAB039D735 __libc_start_main Unknown Unknown
epw.x 0000000020011469 Unknown Unknown Unknown
=====================================

The epw.in file is as below:
=======================================
&inputepw
prefix = 'GaSb'
amass(1) = 69.723
amass(2) = 121.76
outdir = './'

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

elph = .true.
kmaps = .true.
etf_mem = 1

nbndsub = 8
! bands_skipped = 'exclude_bands = 9:16'

dis_win_max = 15.00
dis_froz_max= 8.00

lifc = .true.
asr_typ = 'crystal'
restart = .true.
restart_step= 10000

vme = .true.

wannierize = .false.
use_ws = .true.
lpolar = .true.
num_iter = 5000
wdata(1) = 'bands_plot = .true.'
wdata(2) = 'begin kpoint_path'
wdata(3) = 'L 0.50 0.00 0.00 G 0.00 0.00 0.00'
wdata(4) = 'G 0.00 0.00 0.00 X 0.50 0.50 0.00'
wdata(5) = 'X 0.50000 0.50000 0.0000 K 0.37500 0.75000 0.3750'
wdata(6) = 'K 0.37500 0.75000 0.3750 G 0.00000 0.00000 0.0000'
wdata(7) = 'end kpoint_path'
wdata(8) = 'bands_plot_format = gnuplot'
wdata(9) = 'guiding_centres = .true.'
wdata(10) = 'dis_num_iter = 2000'
wdata(11) = 'num_print_cycles = 100'
wdata(12) = 'dis_mix_ratio = 0.5'
wdata(13) = 'use_ws_distance = T'
wdata(14) = 'conv_window = 10'
wdata(15) = 'conv_tol = 1.0E-10'
iprint = 2
proj(1) = 'Ga:sp3'
proj(2) = 'Sb:sp3'

efermi_read = .true.
fermi_energy= 5.4530 ! eV

! highest occupied, lowest unoccupied level (ev): 4.9698 5.5252 --> nscf.out
! Fermi energy coarse grid = 4.969841 eV


! eig_read = .true.

elecselfen = .false.
phonselfen = .false.
iverbosity = 0

iterative_bte = .false.
int_mob = .false.
carrier = .true.
ncarrier = 1E13
vme = .true.
lphase = .true.

scattering_serta = .true.
scattering = .true.

selecqread = .false.
epmatkqread = .false.


! scissor = 0.2
! nstemp = 5
temps = 200 300 400
mp_mesh_k = .true.


! Valence band maximum = 4.969840 eV
! Conduction band minimum = 5.525225 eV


band_plot = .false.

fsthick = 0.5d0
degaussw = 0.010

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

! filqf = './LGXKG-380.klist'
! filkf = './LGXKG-380.klist'
! filqf = './200000-kpt-crystal-voro2'
! filkf = './85527-kpt-crystal-multi-cauchy-voro'

nk1 = 6
nk2 = 6
nk3 = 6

nq1 = 6
nq2 = 6
nq3 = 6

nkf1 = 20
nkf2 = 20
nkf3 = 20

nqf1 = 20
nqf2 = 20
nqf3 = 20

! rand_k = .true.
! rand_nk = 8000

! rand_q = .true.
! rand_nq = 64000


/
=======================================


The epw.out file crashes after evaluating the Fermi levels corresponding to the temp and carrier concentration:

===========================================
A selecq.fmt file was found but re-created because selecqread == .FALSE.
We only need to compute 8000 q-points

Valence band maximum = 4.905355 eV
Conduction band minimum = 5.626709 eV

Temperature 200.000 K
Mobility CB Fermi level = 5.400225 eV

Temperature 300.000 K
Mobility CB Fermi level = 5.278715 eV

Temperature 400.000 K
Mobility CB Fermi level = 5.149165 eV

===================================================================
Scattering rate
===================================================================


Fermi Surface thickness = 0.500000 eV
This is computed with respect to the fine Fermi level 5.453000 eV
Only states between 4.953000 eV and 5.953000 eV will be included

Application 24851008 exit codes: 174
Application 24851008 resources: utime ~16s, stime ~2s, Rss ~24192, inblocks ~742, outblocks ~200

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

The fine grid size is chosen just for testing. Any help with the issue would be great.

Thanks,

Nandan.

BTW I am using the latest version of QE and EPW.

Nandan.