nkf and degaussw conversion

[ilias-serifi]

Hi there
i continue my calculations to have the good convergence can you help me to found the good parameters

in bibliography lambda = 1.2
and Tc = 6.2 k

for my calculations

Code: Select all

degaussw    = 2 ! eV
  degaussq    = 0.05 ! meV
nkf1        = 16
 nkf2        = 10
 nkf3        = 1

  nqf1        = 8
  nqf2        = 5
  nqf3        = 1
  
  nk1         = 32
  nk2         = 20
  nk3         = 1

  nq1         = 16
  nq2         = 10
  nq3         = 1

i found

Code: Select all

===================================================================
     Eliashberg Spectral Function in the Migdal Approximation
     ===================================================================

     lambda :   68.8009629
     lambda_tr :   17.8459724
 
     Estimated Allen-Dynes Tc
 
     logavg =    0.0003119 l_a2F =   67.7951796
     mu =   0.10 Tc =        13.296098138156 K
     mu =   0.12 Tc =        13.091792641813 K
     mu =   0.14 Tc =        12.885065190021 K
     mu =   0.16 Tc =        12.675899122773 K
     mu =   0.18 Tc =        12.464279556359 K
     mu =   0.20 Tc =        12.250193599057 K

Best

[liu xinbao]

I think your degaussw maybe too high, conversion with 10meV was common in the literature in my opinion.
And your interpolated k-mesh is too small, for 2D materials, 100x100x1 may be even insufficient not to mention 16x10

[ilias-serifi]

Hi

i still look for the convergence of the values of lambda and Tc

Code: Select all

 fsthick     = 15 ! eV 
  eptemp      = 0.075 ! K (same as PRB 76, 165108)
  degaussw    = 0.001 ! eV
  degaussq    = 0.5 ! meV
  dvscf_dir   = '../phonon/save/'
  filukk      = './Al.ukk'
!  filkf       = 'Al_band.kpt'

 nkf1        = 128
 nkf2        = 100
 nkf3        = 1

  nqf1        = 256
  nqf2        = 160
  nqf3        = 1
  
  nk1         = 32
  nk2         = 20
  nk3         = 1

  nq1         = 16
  nq2         = 10
  nq3         = 1
 /

and i get

Code: Select all

 Eliashberg Spectral Function in the Migdal Approximation
     ===================================================================

     lambda :  397.9643105
     lambda_tr :   69.0616167
 
     Estimated Allen-Dynes Tc
 
     logavg =    0.0000780 l_a2F =  460.2368710
     mu =   0.10 Tc =         3.378886439228 K
     mu =   0.12 Tc =         3.328762409069 K
     mu =   0.14 Tc =         3.278046064104 K
     mu =   0.16 Tc =         3.226732928834 K
     mu =   0.18 Tc =         3.174818909270 K
     mu =   0.20 Tc =         3.122300340249 K

any suggestion to help ? i should get a lambda around 1.5


Best

[ilias-serifi]

hi all

any suggestion the solve the problem