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### Solve anisotropic Eliashberg equations

Posted: Sun Oct 10, 2021 5:44 am
Recently,i had a problem with Solve Anisotropic Eliashberg Equations, where no error file was reported after an interrupt to the calculation process and got stuck in the output line below. What could be the problem?

Code: Select all

``````

Pade approximant of anisotropic Eliashberg equations from imaginary-axis to real-axis
Cutoff frequency wscut =     1.0000

554            NaN            NaN

Convergence was reached for N =    554 Pade approximants
``````

and the input files is :

Code: Select all

``````&inputepw
prefix      =  '  '
amass(1)    = ,
outdir      = './outdir/'
ep_coupling = .true.
elph        = .true.
kmaps       = .true.
epwwrite = .false.
wannierize  = .false.
!  num_iter    = 0
dis_froz_min=
dis_froz_max=
proj(1) = ' '
wdata(1) = 'Begin Kpoint_Path'
wdata(2) = 'G 0.00 0.00 0.00   M 0.00 0.50 0.00'
wdata(3) = 'M 0.00 0.50 0.00   K 0.333 0.333 0.00'
wdata(4) = 'K 0.333 0.333 0.0  G 0.00 0.00 0.00'
wdata(5) = 'End Kpoint_Path'
wdata(6) = 'bands_plot = .true.'
wdata(7) = 'bands_num_points = 55'
wdata(8) = 'guiding_centres = .true.'
wdata(9) = 'dis_num_iter = 5000'
bands_skipped = 'exclude_bands = 1:25'

system_2d=.true.
etf_mem     =  1
nbndsub     =  ,
iverbosity  = 2
eps_acustic = 2.0    ! Lowest boundary for the phonon frequency
ephwrite    = .true. ! Writes .ephmat files used when Eliasberg = .true.
fsthick     = 0.1  ! eV
degaussw    = 0.01 ! eV
nsmear      = 1
nqsmear     = 1
delta_smear = 0.01 ! eV
degaussq     = 0.5 ! meV
nqstep       = 500
eliashberg  = .true.
laniso = .true.
limag = .true.
conv_thr_iaxis = 1.0d-4
!  max_memlt = 1.40d0
!  asr_typ = 'crystal'
delta_approx = .true.,
!  elecselfen = .true.,
phonselfen = .true.,
!  a2f = .true. ,
wscut = 1.0   ! eV   Upper limit over frequency integration/summation in the Elisashberg eq
nstemp   = 11     ! Nr. of temps
temps    = 3.00 13.00 ! K  provide list of temperetures OR (nstemp and temps = tempsmin  tempsmax for even space mode)
nsiter   = 500
muc     = 0.21246
dvscf_dir   = '../../test-phonon/save'

nk1         = 12
nk2         = 12
nk3         = 1
nq1         = 6
nq2         = 6
nq3         = 1

!  mp_mesh_k = .true.
nkf1 = 60
nkf2 = 60
nkf3 = 1
nqf1 = 60
nqf2 = 60
nqf3 = 1
/
``````

Ihad try to change the "max_memlt" When I came across this problem ,But it's not this parameter. So how can I solve this problem,Thanks you ! Best wish!

### Re: Solve anisotropic Eliashberg equations

Posted: Sun Oct 10, 2021 6:25 pm
Hi dhw,

It looks like you do not have enough Matsubara points in the Pade continuation. I am not sure which version of the code you are using, if it is the latest version, we have introduced a new input variable 'npade', see below;
https://gitlab.com/QEF/q-e/-/blob/devel ... n.f90#L262

The default value is 90%, see below;
https://gitlab.com/QEF/q-e/-/blob/devel ... o.f90#L154

I think, increasing it will solve your issue.

Happy EPWing,
Hari

### Re: Solve anisotropic Eliashberg equations

Posted: Wed Oct 20, 2021 9:36 am
Hi. Thank you very much for your answer. I used QE6.6 version, which was also used in calculation of other systems before, so I have never used this parameter. I will try this parameter is also available in QE6.6 version.