EPW crashes in cdiagh2 subroutine in SOC calculation

Dear EPW creators and users,

I want to calculate the spectral function a2F with EPW and have a working setup for calculations without spin-orbit coupling (SOC). Sadly EPW crashes every time I try to include SOC with the following error message:

**Code:**

...

Using random q-mesh: 50000

Size of q point mesh for interpolation: 50000

Using random k-mesh: 200000

Size of k point mesh for interpolation: 400000

Max number of k points per pool: 1390

Fermi energy coarse grid = 10.770282 eV

Skipping the first 40 bands:

The Fermi level will be determined with 0.02725 electrons

Fermi energy is calculated from the fine k-mesh: Ef = 10.747310 eV

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

ibndmin = 1 ebndmin = 0.776

ibndmax = 6 ebndmax = 1.114

Number of ep-matrix elements per pool : 375300 ~= 2.86 Mb (@ 8 bytes/ DP)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Error in routine cdiagh2 (14):

info =/= 0

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

stopping ...

Wannierization for both bands and phonons seems to work (use the new pp.py file from Gitlab after Nov 2018 for SOC calculations if you use QE 6.3 and EPW 5!), but here I am stuck. I already checked the source code at

https://gitlab.com/QEF/q-e/blob/develop/PHonon/PH/rigid.f90, but that did not help as well.

My epw.in looks as follows:

**Code:**

--

&inputepw

prefix = 'kto',

outdir = './'

elph = .true.

epwwrite = .true.

epwread = .false.

kmaps = .false.

nbndsub = 6

nbndskip = 40

wannierize = .true.

dis_win_max = 15.160

dis_froz_max = 14.946

dis_froz_min = 10.550

dis_win_min = 8.480

proj(1) = 'Ta:l=2,mr=2,3,5'

wdata(1) = 'bands_plot = .true.'

wdata(2) = 'begin kpoint_path'

wdata(3) = 'G 0.00 0.00 0.00 X 0.50 0.00 0.00'

wdata(4) = 'X 0.50 0.00 0.00 M 0.50 0.50 0.00'

wdata(5) = 'M 0.50 0.50 0.00 G 0.00 0.00 0.00'

wdata(6) = 'G 0.00 0.00 0.00 R 0.50 0.50 0.50'

wdata(7) = 'R 0.50 0.50 0.50 X 0.50 0.00 0.00'

wdata(8) = 'X 0.50 0.00 0.00 M 0.50 0.50 0.00'

wdata(9) = 'M 0.50 0.50 0.00 R 0.50 0.50 0.50'

wdata(10) = 'end kpoint_path'

wdata(11) = 'bands_plot_format = gnuplot'

iverbosity = 0

eptemp = 0.005 ! K (std: 300.d0)

degaussw = 0.025 ! eV (std: 0.025)

degaussq = 0.050 ! meV (std: 0.05)

a2f = .true.

phonselfen = .true.

! lifc = .true.

dvscf_dir = '../phonons/save'

rand_k = .true.

rand_nk = 200000

rand_q = .true.

rand_nq = 50000

nk1 = 12

nk2 = 12

nk3 = 12

nq1 = 4

nq2 = 4

nq3 = 4

/

10 cartesian

0.000000000 0.000000000 0.000000000

0.000000000 0.000000000 0.250000000

0.000000000 0.000000000 -0.500000000

0.000000000 0.250000000 0.250000000

0.000000000 0.250000000 -0.500000000

0.000000000 -0.500000000 -0.500000000

0.250000000 0.250000000 0.250000000

0.250000000 0.250000000 -0.500000000

0.250000000 -0.500000000 -0.500000000

-0.500000000 -0.500000000 -0.500000000

Am I doing something wrong here or is this some bug in EPW? As a note, I was able to calculate SOC structures with QE 6.2.1, albeit with a probably slightly different input file some months ago...