exc-pol self-consistent calc converges to 0.0 eV

[Agathyan]

Dear all,

I am attempting to calculate the exciton-polaron self-energy using EPW v6.0. First epw1 run done successfully.

When I run the restart step to calculate the exciton-polaron properties (epw2.in with explrn = .true.), the self-consistent calculation converges immediately after 2 iterations, returning exactly 0.0 for both the Eigenvalue and Total Energy. The run then completes and exits normally without any crash or error message.

Could you help me understand why the initial exciton states are being read or evaluated as zero?

epw2.out:

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Start the excitonic polaron self-consistent calculation.
     Iteration    Eigenvalue (eV)    Total Energy (eV)    Error (eV).
         1          0.00000000          0.00000000
         2          0.00000000          0.00000000          0.00000000
     Convergence achieved. The converged eigenvalue and total energy are:           0.00000000          0.00000000
     Q point holding the lowest-energy exciton:           0.00000000          0.00000000          0.00000000
     Total energy referenced to the lowest-energy exciton at Q=0:           0.00000000

Below are my input files:

epw1.in

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&inputepw
  prefix      = 'AB'
  outdir      = './'
  dvscf_dir   = './save/'

  elph        = .true. 
  epwwrite    = .true.
  epwread     = .false.
  epbwrite    = .true.
  epbread     = .false.
  etf_mem     = 0
  epw_memdist = .true.

  wannierize   = .true.
  eig_read     = .true.
  nbndsub      = 12 
  num_iter     = 20000
  iprint       = 2

  proj(1)      = 'A : s, p'
  proj(2)      = 'B  : s, p'

  dis_win_max  = 6.872429
  dis_froz_max = 3.013135
  dis_froz_min = -9.391191
  dis_win_min  = -22.338782
  
  wdata(1)     = 'bands_plot = .true.'
  wdata(2)     = 'begin kpoint_path'
  wdata(3)     = 'G 0.0000 0.0000 0.0000 M 0.5000 0.0000 0.0000'
  wdata(4)     = 'M 0.5000 0.0000 0.0000 K 0.3333 0.3333 0.0000'
  wdata(5)     = 'K 0.3333 0.3333 0.0000 G 0.0000 0.0000 0.0000'
  wdata(6)     = 'end kpoint_path'
  wdata(7)     = 'bands_plot_format = gnuplot xmgrace'
  wdata(8)     = 'guiding_centres = .true.'
  wdata(9)     = 'dis_num_iter      = 10000'
  wdata(10)    = 'dis_conv_window  = 10'
  wdata(11)    = 'dis_conv_tol     = 1.0e-9'
  wdata(12)    = 'conv_window  = 10'
  wdata(13)    = 'conv_tol     = 1.0e-9'

  wannier_plot = .true.
  wannier_plot_supercell = 6 6 2
  wannier_plot_radius = 4.0

  lpolar                 = .true. 
  exciton                = .true.
  explrn                 = .false.

  negnv_explrn = 20 
  nbndv_explrn = 6   
  nbndc_explrn = 6   

  nk1 = 10
  nk2 = 10
  nk3 = 1 
  nq1 = 10
  nq2 = 10
  nq3 = 1
  
  asr_typ = 'crystal'
  use_ws  = .true.  
  lifc    = .false.

  band_plot              = .true.
  filkf                  = './path.kpt'
  filqf                  = './path.kpt'
/

epw2.in

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&inputepw
  prefix                 = 'AB'
  outdir                 = './'
  dvscf_dir              = './save/'

  elph         = .true.
  epbwrite     = .false.
  epbread      = .false.
  epwwrite     = .false.
  epwread      = .true.
  etf_mem      = 0

  wannierize   = .false.
  nbndsub      = 12

  lpolar       = .true.  
  exciton      = .true.
  explrn       = .true.

  negnv_explrn = 20 
  nbndv_explrn = 6   
  nbndc_explrn = 6   

  init_plrn    = 5
  niter_plrn   = 500
  conv_thr_plrn = 1.0d-6

  nk1                    = 10
  nk2                    = 10
  nk3                    = 1
  nq1                    = 10
  nq2                    = 10
  nq3                    = 1

  band_plot              = .true.
  filkf                  = './path_interp.kpt'
  filqf                  = './path_interp.kpt'

  use_ws  = .true.  
/