&control
    calculation = 'scf'
    restart_mode = 'from_scratch'
    prefix = 'si'
    tstress = .false.
    tprnfor = .true.
    outdir = '/home/jyhuang/WS_QE/scratch/' ,
    wfcdir = '/home/jyhuang/WS_QE/scratch/' ,
    pseudo_dir = '/home/jyhuang/WS_QE/pseudo/' ,
 /
 &system
    ibrav = 2
    celldm(1) = 10.31335
    nat = 2
    ntyp = 1
    ecutwfc = 25
 /
 &electrons
    diagonalization = 'david'
    mixing_mode = 'plain'
    mixing_beta = 0.7
    conv_thr =  1.e-8
 /
ATOMIC_SPECIES
Si  28.0855 Si.pbe-hgh.UPF

ATOMIC_POSITIONS alat
Si  0.00   0.00   0.00
Si  0.25   0.25   0.25

K_POINTS automatic
4 4 4    1 1 1