[Pw_forum] convergence not achieved .related problem

[m rostami]

Dear users
I have been trying to relax a graphene structure with a vacancy but
many erros stoped optimization and convergence not achieved.like

1. Efermy cannot braket :
2. to0 many bands not coveraged

for solving the errors I have chenged these parametrs

 increasing ecutoff to 60 and ecuthro to 720 .increasing edeguss to
0.07 and changing diagnolization from cg to david  . I have tested
smearing for m-v and mp .increasing nbands from   70 to 120  too .but
optimization didnt achived .I appreciate if any one helpe me .

my input file is :
&control
    calculation='relax',
    prefix='graphene'
    pseudo_dir = '/media/espresso-4.2/pseudo/',
    outdir='./tmp/',
    etot_conv_thr=1.0D-3 ,
    forc_conv_thr=1.0D-2 ,

 /
 &system
    ibrav=  4, celldm(1) =13.9506, celldm(3)=1.667,nat=35, ntyp= 1,nbnd=120
   ecutwfc =80.0,ecutrho = 900,
    occupations='smearing',smearing='m-v',degauss=0.07,
 /
 &electrons
  diagonalization='cg',
  conv_thr=1.D-8 ,
  mixing_beta=0.1,
 /
 &ions
 upscale=20,
 /
ATOMIC_SPECIES
C  1.00  C.blyp-mt.UPF
ATOMIC_POSITIONS {angstrom}
    C    0.0071683270    0.0041386380    1.6740000000
 .........
......
K_POINTS  AUTOMATIC
8 8 1 0 0 0


.............................
I am not sure about these questions to0 :.

1.in example 3 the atomic weight for different atoms is set to 1 in
relax process.is this correct? as I did for carbon (ATOMIC_SPECIES
C  1.00  C.blyp-mt.UPF)
I am not sure about k-point .is 8 8 1 0 0 0  enough for this structure
with 10 A` vaccum .

how many nbands I should for coverage ?

wich diagnbolization is better david or cg ?

mixing_beta should be around 0.1-0.3?


thanks alot

Melika Rostami
Master Student of Sharif University