[QE-users] TDDFPT - EELS: restart generates NaNs

[Levi Keller]

Hello:

Upon restarting a turbo_eels.x calculation, I noted that the value of z1 
was oscillating between 1+0i and NaN + NaNi, while alpha,beta,gamma = 
0,NaN,0 for all iterations after the first.

In the first iteration after restarting, alpha = 0, beta=  gamma = 31.15 
~= ecutwfc/2, and z1=1+0i

my pw.x input in

&CONTROL
   calculation = 'scf'
   prefix='d100',
   pseudo_dir = '../../pseudo/',
   nstep =  55,
   etot_conv_thr = 1.0E-7,
   outdir='d100/'
  /
  &SYSTEM
     ibrav=  2
     celldm(1) = 9.71187
     nat= 2
     ntyp= 2
     nbnd = 8
     occupations  =  'fixed',
     ecutwfc=60.0,
     ecutrho=400.0,
  /
  &ELECTRONS
     diagonalization='david'
     mixing_mode = 'plain'
     mixing_beta = 0.7
     conv_thr =  1.0d-12
  /
ATOMIC_SPECIES
   Li  6.941  Li.pbe-s-rrkjus_psl.0.2.1.UPF
   Cl  35.453 Cl.pbe-n-rrkjus_psl.0.1.UPF
ATOMIC_POSITIONS alat
   Li 0.5 0.5 0.5
   Cl 0.0 0.0 0.0
K_POINTS automatic
   8 8 8 1 1 1

and my turbo_eels.x input is

&lr_input
   prefix = 'd100',
   outdir='d100/',
   restart_step=250,
   restart=.true.
/
&lr_control
   itermax=1000
   q1=3.25626
   q2=0
   q3=3.25626
/u

let me know if you need any other diagnostic information. I am running 
qe-6.3MaX on 60 cpus on a system employing SLURM.

Levi Keller
Helsinki University