[Pw_forum] problem of scf calculation under electric field

[shypirate]

Dear all,
Sorry to bother you again.
I want to calculate band structure under electric field. After set dipfield=.true. and other settings remain unchanged, self-consistent calculation has trouble to converge. In each self-consistent calculation step, there are several "c_bands: * eigenvalues not converged" warning messages. And, after several self-consistent steps, usually 3 steps, program stops with error message: "too many eigenvalues not converged". Could you give me some advice about this error? Where may be the error in my input file? number of k-points ? My input file for pw.x is like this:

&control
calculation = 'relax',
nstep=200,
tprnfor = .TRUE.,
tefield = .TRUE.,
dipfield = .TRUE.,
prefix = 'relax',
pseudo_dir = '/home/ypwang/espresso/pseudo/',
outdir = './out',
/
&system
ibrav = 6, celldm(1) = 7.35, celldm(3) = 8, nat = 20, ntyp = 5,
ecutwfc = 40.0, ecutrho = 480,
occupations = 'smearing', degauss = 0.005, smearing = 'mv',
edir =3,
emaxpos = 0.9,
eopreg = 0.1,
eamp = 0.00
/
&electrons
diagonalization = 'cg'
mixing_mode = 'local-TF'
mixing_beta = 0.3
conv_thr = 1.0d-8
/
&IONS
bfgs_ndim = 7
/
ATOMIC_SPECIES
...

K_POINTS automatic
4 4 2 1 1 1

Thanks in advance!

2009-10-12 



shypirate 
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