About double-grid method for the electron-phonon coupling

[bowen yang]

Dear all,
when i try Double-grid method for the electron-phonon coupling, encounter a error as below.

[ERROR] STOP signal received while in[06] == Electron-Phonon Databases ==
[ERROR] Incorrect q-point in ../si.freq

Follow the tutorails, using a random q-sampling generated by ypp -k r,
bzgrids # [R] BZ Grid generator
Random_Grid # [R] Random grids
OutputAlat= 0.000000 # [a.u.] Lattice constant used for "alat" ouput format
#NoWeights # Do not print points weight
cooOut= "alat" # Points coordinates (out) cc/rlu/iku/alat
BZ_random_Nk=500 # BZ Random points to be printed
#DoNotDistr # Do not generate random points around the k-points of the BZ

with modify the BZ_random_Nk=500,and cooOut unit as "alat"
then run ypp, i get a o.random_k_pts file,
cut off some of them as below
c1 c2 c3 wt
0.565529428E-1 0.450957045E-1 0.172607582E-1 1.00000000
-0.419358723E-1 0.740709826E-1 0.124733374 1.00000000
0.295189973E-1 0.441811942E-1 -0.148290813 1.00000000
-0.666107461E-1 0.290443990E-1 0.492197037 1.00000000
-0.317108519E-1 -0.247512460E-1 -0.331602782 1.00000000
0.103952084E-1 0.981000364E-1 0.610097289 1.00000000
0.132344812E-1 0.247819409 -0.215946939E-1 1.00000000
-0.178358167 -0.909774154E-1 -0.132978156 1.00000000
0.263332039 -0.790505484E-1 -0.465942845E-1 1.00000000
0.164940935E-1 -0.135771319 0.235282611E-1 1.00000000
0.173803419 0.405180715E-1 0.929508358E-2 1.00000000
-0.830965489E-1 0.917422250E-1 -0.256911991E-2 1.00000000
-0.637554526E-1 0.250151843 0.202618733 1.00000000
...................
...................
this exactly i used q points list in a matdyn file, no any modify.
It is correct my method?
My previous steps as follow:
step1: scf
step1:nscf
step3: phonons
&inputph
verbosity = 'high',
tr2_ph = 1e-12,
amass(1) = 28.085,
prefix = 'si-1x1'
fildvscf = 'si-dvscf'
fildyn = 'bulk-si.dyn'
electron_phonon = 'dvscf',
epsil = .false.
ldisp = .true.
trans = .true.
nq1=6, nq2=6, nq3=6
/
step4: dvscf
&inputph
verbosity = 'high',
tr2_ph = 1e-12,
amass(1) = 28.085,
prefix = 'si-1x1'
fildvscf = 'si-dvscf'
fildyn = 'bulk-si.dyn'
electron_phonon = 'yambo',
epsil = .false.
ldisp = .true.
trans = .false.
nq1=6, nq2=6, nq3=6
/
step5: q2r.x
&input
fildyn='bulk-si.dyn', zasr='simple', flfrc='si-666.fc'
/
step6: matdyn.x
&input
asr='simple'
flfrc='si-666.fc',
flfrq='si.freq',
dos=.false.,
fldos='si.dos',
deltaE=1.d0,
/
432
0.565529428E-1 0.450957045E-1 0.172607582E-1 1.00000000
-0.419358723E-1 0.740709826E-1 0.124733374 1.00000000
0.295189973E-1 0.441811942E-1 -0.148290813 1.00000000
-0.666107461E-1 0.290443990E-1 0.492197037 1.00000000
-0.317108519E-1 -0.247512460E-1 -0.331602782 1.00000000
0.103952084E-1 0.981000364E-1 0.610097289 1.00000000
.................................................................................
Futhermore, i have another questions, in step6, the parameters dos, in QE, if dos=.true. calculate phonon Density of States (DOS)
using tetrahedra and a uniform q-point grid
NB: may not work properly in noncubic materials.
if .false. calculate phonon bands from the list of q-points
supplied in input (default)
Does this mean that only the q-point list can be used in noncubic materials?
Best regards！
Yang

[claudio]

Dear Yang

did you read the addition q-points using ypp_ph -g d ?

Regarding the dos, this is not a problem, for Yambo the important point
is that matdyn interpolate phonons on a regular grid, than the fact the dos calculated
from QE is not exact is not a problem

let me know, in case I will try to run again the tutorial and fix it
best
Claudio