[Pw_forum] convergence issues

[Jonas Baltrusaitis]

Hi,

the simplest polymer system wouldn'd converge the first SCF cycle after 100 iterations. I would appreciate any comments

Jonas
University of Iowa

iteration #100     ecut=    25.00 Ry     beta=0.50
     Davidson diagonalization with overlap
     ethr =  4.79E-07,  avg # of iterations =  8.9

     negative rho (up, down):  0.466E-01 0.000E+00

     total cpu time spent up to now is  35393.00 secs

     total energy              =  -323.97794967 Ry
     Harris-Foulkes estimate   =  -323.97794161 Ry
     estimated scf accuracy    <     0.00009414 Ry

     End of self-consistent calculation

     convergence NOT achieved after 100 iterations: stopping

INPUT

 &control
    calculation='relax',
    prefix='44tpcb_PBE_optimization',
    pseudo_dir='/share/apps/espresso-4.0.4/pseudo/',
    outdir='/home/jbaltrus/atom-lsda/',
    nstep=200
 /
 &system
   ibrav=12,
   nat=38,
   ntyp=4,
   a=11.367,
   b=9.749,
   c=14.273,
   cosab=-0.36922777,
   ecutwfc=25.0
 /
 &electrons
   mixing_beta=0.5D0,
   conv_thr = 1.D-8
 /
 &ions
ion_dynamics = ’none’
 /
ATOMIC_SPECIES
O     15.9994    O.pbe-van_ak.UPF
H      1.00794   H.pbe-van_ak.UPF
N     14.00674   N.pbe-van_ak.UPF
C     12.0107    C.pbe-van_ak.UPF
ATOMIC_POSITIONS
O       0.5906d0        0.1506d0        -0.0226d0
H       0.5262d0        0.1780d0        -0.0127d0
O       0.4362d0        0.4661d0        -0.3017d0
H       0.3777d0        0.4763d0        -0.2797d0
N       0.3866d0        0.2227d0        0.0225d0
N       -0.2359d0       0.4717d0        0.2407d0
C       0.5970d0        0.2136d0        -0.1054d0
C       0.5078d0        0.3087d0        -0.1618d0
H       0.4379d0        0.3310d0        -0.1433d0
C       0.5203d0        0.3707d0        -0.2445d0
C       0.6226d0        0.3399d0        -0.2715d0
H       0.6319d0        0.3834d0        -0.3279d0
C       0.7110d0        0.2453d0        -0.2152d0
H       0.7808d0        0.2233d0        -0.2338d0
C       0.6996d0        0.1818d0        -0.1322d0
H       0.7612d0        0.1172d0        -0.0939d0
C       0.3805d0        0.3404d0        0.0679d0
H       0.4571d0        0.3888d0        0.1017d0
C       0.2693d0        0.3958d0        0.0688d0
H       0.2707d0        0.4799d0        0.1028d0
C       0.1556d0        0.3288d0        0.0201d0
C       0.1626d0        0.2053d0        -0.0245d0
H       0.0878d0        0.1537d0        -0.0576d0
C       0.2765d0        0.1569d0        -0.0215d0
H       0.2778d0        0.0710d0        -0.0525d0
C       0.0295d0        0.3910d0        0.0066d0
H       -0.0351d0       0.3174d0        -0.0023d0
C       0.0213d0        0.4989d0        0.0827d0
H       0.1082d0        0.5246d0        0.1298d0
C       -0.0637d0       0.4764d0        0.1406d0
C       -0.0454d0       0.5536d0        0.2264d0
H       0.0275d0        0.6101d0        0.2536d0
C       -0.1322d0       0.5488d0        0.2720d0
H       -0.1172d0       0.6043d0        0.3299d0
C       -0.2497d0       0.3918d0        0.1611d0
H       -0.3209d0       0.3323d0        0.1380d0
C       -0.1675d0       0.3903d0        0.1106d0
H       -0.1821d0       0.3300d0        0.0551d0
K_POINTS {automatic}
4 4 4 0 0 0