monolayer LiC6 gap distribution
Posted: Thu Jul 25, 2019 12:57 pm
Hello,
I have performed EPW calculations for monolayer LiC6 for which Roxana Margine kindly shared her input with me.
I have several questions regarding the obtained result.
First of all I want to note that my run has crashed at the temperature of 5.1 K with the following error message:
Convergence was not reached in nsiter = 150
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine sum_eliashberg_aniso_iaxis (1):
increase nsiter or reduce conv_thr_iaxis
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Even though I can indeed increase the number of iterations I don't really believe it will converge. So could you please tell me if there is a different remedy for it?
Since some of the temperatures ran smoothly I could already try to compare some results.
As the benchmark naturally I used the Roxana's paper on LiC6 and in particular the gap vs temperature graph. (link to the image https://ibb.co/kmKLVwq)
When I plot my gap distribution file called "graphene.imag_aniso_gap0_002.00" which contains information for T = 2 K I get something that is different from the picture in the article (link to the picture https://ibb.co/CwKBX3N) . The shape is different and the gap barely reaches 0.8 meV whereas the article version is more or less centered around 0.8 meV. Could you plese give me a hint where I might have made a mistake?
Here is my input just in case:
I have performed EPW calculations for monolayer LiC6 for which Roxana Margine kindly shared her input with me.
I have several questions regarding the obtained result.
First of all I want to note that my run has crashed at the temperature of 5.1 K with the following error message:
Convergence was not reached in nsiter = 150
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine sum_eliashberg_aniso_iaxis (1):
increase nsiter or reduce conv_thr_iaxis
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Even though I can indeed increase the number of iterations I don't really believe it will converge. So could you please tell me if there is a different remedy for it?
Since some of the temperatures ran smoothly I could already try to compare some results.
As the benchmark naturally I used the Roxana's paper on LiC6 and in particular the gap vs temperature graph. (link to the image https://ibb.co/kmKLVwq)
When I plot my gap distribution file called "graphene.imag_aniso_gap0_002.00" which contains information for T = 2 K I get something that is different from the picture in the article (link to the picture https://ibb.co/CwKBX3N) . The shape is different and the gap barely reaches 0.8 meV whereas the article version is more or less centered around 0.8 meV. Could you plese give me a hint where I might have made a mistake?
Here is my input just in case:
Code: Select all
epwcalculation
&inputepw
prefix = 'graphene',
amass(1) = 12.01078
amass(2) = 6.941
outdir = './'
dvscf_dir = '../phonons/save/'
ep_coupling = .true. !run eph calculation
elph = .true. !calculate eph coefficients
kmaps = .false. !Generate the map k+q --> k for folding the rotation matrix U(k+q). Set to "false" to calculate it, "true" to read it
epbwrite = .true. !If epbwrite = .true., the electron-phonon matrix elements
epbread = .false. ! in the coarse Bloch representation and relevant data (dyn
! matrices) are written to disk.
epwwrite = .true. ! If epwwrite = .true., the electron-phonon matrix elements
! in the coarse Wannier representation and relevant data (dyn
! matrices) are written to disk.
! Each pool reads the same file.
epwread = .false. ! If epwread = .true., the electron-phonon matrix elements
! in the coarse Wannier representation are read from the 'epwdata.fmt' and 'XX.epmatwpX' files.
! Each pool reads the same file. It is used for a restart calculation and requires kmaps = .true.
! A prior calculation with epwwrite = .true is also required.
etf_mem = 1 ! If etf_mem == 0, then all the fine Bloch-space el-ph matrix elements
! are store in memory (faster).
! When etf_mem == 1, more IO (slower) but less memory is required.
! When etf_mem == 2, an additional loop is done on mode for the fine grid interpolation
! part. This reduces the memory further by a factor "nmodes".
nbndsub = 15 !Number of wannier functions to utilize.
nbndskip = 1 ! The number of bands lying below the disentanglement
!window in the calculation of the Wannier functions.
!This quantity is necessary to correctly determine
!the Fermi energy.
wannierize = .true.
num_iter = 2000
dis_win_min = -20.0
dis_froz_min = -20.0
dis_froz_max = 2.45
proj(1) = 'f=0.333301340,0.000000000,0.000000000:sp2,pz'
proj(2) = 'f=0.666698660,0.000000000,0.000000000:pz'
proj(3) = 'f=0.000000000,0.333301340,0.000000000:sp2,pz'
proj(4) = 'f=0.333301340,0.333301340,0.000000000:pz'
proj(5) = 'f=0.000000000,0.666698660,0.000000000:pz'
proj(6) = 'f=0.666698660,0.666698660,0.000000000:sp2,pz'
wdata(1) = 'dis_num_iter = 5000'
wdata(2) = 'dis_mix_ratio = 0.9'
wdata(3) = 'guiding_centres = .true.'
wdata(4) = 'bands_plot = true'
wdata(5) = 'begin kpoint_path'
wdata(6) = 'G 0.000000000 0.000000000 0.000000000 M 0.500000000 0.000000000 0.000000000'
wdata(7) = 'M 0.500000000 0.000000000 0.000000000 K 0.333333333 0.333333333 0.000000000'
wdata(8) = 'K 0.333333333 0.333333333 0.000000000 G 0.000000000 0.000000000 0.000000000'
wdata(9) = 'end kpoint_path'
wdata(10) = 'num_print_cycles = 50'
iverbosity = 2
!elinterp = .true.
!phinterp = .true.
!tshuffle2 = .true.
!tphases = .false.
!parallel_k = .true.
! parallel_q = .false.
eps_acustic = 5.0
ephwrite = .true. ! originally .false.
eliashberg = .true.
fsthick = 0.4 ! eV / Energy window around the Fermi level that is taken into account
eptemp = 300 ! Array of smearing occupations for the Fermi occupation in [K].
degaussw = 0.10 ! eV Smearing in the energy-conserving delta functions in [eV]
nsmear = 1 !Number of different smearings used to calculate
! the phonon self-energy
delta_smear = 0.04 ! eV Change in the energy for each additional smearing in the
! phonon self-energy in [eV]
degaussq = 0.5 ! meV Smearing for sum over q in the e-ph coupling in [meV]
nqstep = 500 ! Number of steps used to calculate the a2f
delta_qsmear = 0.1 ! meV Change in the energy for each additional smearing in the a2f in [meV].
dvscf_dir = './save'
laniso = .true.
limag = .true.
lpade = .true. ! originally commented out
conv_thr_iaxis = 1.0d-3
max_memlt = 16.0 ! maximum memory per pool
wscut = 0.6348209988
! gap_edge = 0.0005
nstemp = 12
temps(1) = 2.00
temps(2) = 2.50
temps(3) = 3.00
temps(4) = 3.50
temps(5) = 4.00
temps(6) = 4.50
temps(7) = 5.00
temps(8) = 5.10
temps(9) = 5.20
temps(10) = 5.30
temps(11) = 5.40
temps(12) = 5.50
nsiter = 150
muc = 0.16
nk1 = 12
nk2 = 12
nk3 = 1
nq1 = 6
nq2 = 6
nq3 = 1
mp_mesh_k = .true.
nkf1 = 120
nkf2 = 120
nkf3 = 1
nqf1 = 60
nqf2 = 60
nqf3 = 1
/
7 cartesian
0.000000000 0.000000000 0.000000000 0.055555556
0.000000000 0.192450090 0.000000000 0.333333333
0.000000000 0.384900179 0.000000000 0.333333333
0.000000000 -0.577350269 0.000000000 0.166666667
0.166666667 0.288675135 0.000000000 0.333333333
0.166666667 0.481125224 0.000000000 0.666666667
0.333333333 0.577350269 0.000000000 0.111111111