 &control
    calculation = 'scf'
    restart_mode='from_scratch',
    prefix='di',
    pseudo_dir='/home/arash/PW-pseudo',
    outdir='/home/arash/tmp'
 /
 &system    
    ibrav=  2, celldm(1) =6.1, nat=  2, ntyp= 1,
    ecutwfc =40.0, 
 /
 &electrons
    diagonalization='david'
    mixing_mode = 'plain'
    mixing_beta = 0.7 
    conv_thr =  1.0d-13
 /
ATOMIC_SPECIES
 C  12.0  C.pz-vbc.UPF
ATOMIC_POSITIONS {crystal}
C  -0.125 -0.125 -0.125
C   0.125  0.125  0.125
K_POINTS {automatic}
 12 12 12 0 0 0
