[Pw_forum] Question on el-ph calculations

[Сергей Ерохин]

Dear quantum espresso community,
  I am trying to calculate the critical temperature of superconductivity in boron doped diamond by quantum espresso-5.1. I provide the scf-calculation using 24x10x10 k-points for cell size 4.17x14.35x11.75Å.
For phonon dispersion calculation I use very coarse grid of q-points (3x2x2) because the unit cell have not any symmetry and the calculation will take a lot of time. I have got that lambda dependence strongly changes with increasing of degauss (see attached figure). Would you be so kind to explain me which parameters in input files affect on lambda and how improve my results?  And how can I distinguish the correct value of Tc and lambda from this dependencies?
Thank you in advance!
  Here are my input files
File for scf-calculation
  &control
calculation='scf'
restart_mode='from_scratch',
tstress = .true.
tprnfor = .true.
prefix='c',
pseudo_dir = '.',
outdir='.',
nstep = 200 
wf_collect=.true.,
/
&system
nosym=.false.,
ibrav= 0, 
celldm(1) = 0, 
nat= 18, 
ntyp= 2,
ecutwfc=32.0,
ecutrho=200.0,
occupations='smearing',
smearing='methfessel-paxton', 
degauss=0.05,
la2F = .true.,
CELL_PARAMETERS
0 14.3554 0
4.1796 2.4159 0.0057
0 0 11.7448
ATOMIC_SPECIES
C 12.0108 C.pz-vbc.UPF
B 10.8120 B.pz-vbc.UPF
ATOMIC_POSITIONS crystal
C 0 0 0
…
C 0.5 0.5 0.5
\
K_POINTS automatic 
24 10 10 0 0 0
  File for Electron-phonon coefficients for BC
&inputph
tr2_ph=1.0d-10,
prefix='c',
fildvscf='cdv',
amass(1)=12.0108,
amass(2)=10.8120,
outdir='./',
fildyn='c.dyn',
electron_phonon='interpolated',
trans=.true.,
ldisp=.true.,
nq1=3, nq2=2, nq3=2
alpha_mix(1)=0.7, 
/ --
Sergey Erohin
Student of Moscow Institute of Physics and Technology State University 
9 Institutskiy per., Dolgoprudny, Moscow Region, 141700, Russian Federation


-- 
Сергей Ерохин
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