[Pw_forum] odd # of electrons in primitive cell => metal ?

[sonu kumar]

Dear all QE users,

My primitive unit cell contains odd # of electrons so it should be metallic.
QE code indicates the system to be metallic.

But experimentally it is an insulator with band gap ~1.2 eV.

why am i not able to get the insulating nature of the system?

IS there something wrong in the input file? or in DFT?


###################################################################
PARTs OF input n output file are:

&control
    calculation='scf',             ! relax,scf,vc-relax
    verbosity='high',
    restart_mode='from_scratch',   ! 'from_scratch',
    prefix='CuFeO2',
    !wf_collect=.true.,
    tstress=.true.,
    tprnfor=.true.,
    etot_conv_thr=1.0D-6,
    forc_conv_thr=1.0D-5,

    pseudo_dir = './pseudo',
    outdir='./tmp',
 /

&system
    ibrav=5,celldm(1)=11.31,
    celldm(4)=0.8718,

    nat=  4,
    ntyp= 3,

    !nbnd=24,
    ecutwfc=40,
    ecutrho=400,

    !occupations = 'smearing',
    !degauss = 0.005D0,
    !smearing='gaussian',
    nspin=1,
 /

&electrons
    electron_maxstep=100,
    mixing_mode='local-TF',
    mixing_beta = 0.2,
    conv_thr = 1.0d-12,
    mixing_ndim=8,
    diagonalization='cg',

 /


ATOMIC_SPECIES
Cu  0.0  Cu.pbe-n-van_ak.UPF
Fe  0.0  Fe.pbe-sp-van.UPF
O   0.0  O.pbe-rrkjus.UPF
.....
....


!!!!!!!!!!!!!!!!!!!!!! Part of ouput file
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from electrons : error #         1

     stopping ...
     charge is wrong: smearing is needed
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

#####################################################################


With Kind regards,

Sonu Kumar

Phd Student
Physics Department
Indian Institute of Technology
Delhi-110016, India
web:-http://www.iitd.ac.in/
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