Dear

I have tried to geometric optimization for hexagonal BeO. a lattice parameter was found agree with literature data but c was very different after geometric optimization. I dont know what can i do for this mistake. Any comment? Please find the input code for geometric optimization

&CONTROL

calculation = "vc-relax"

forc_conv_thr = 1.00000e-03

nstep = 100

prefix ="BeO_scf_cal"

verbosity ="high"

restart_mode = "from_scratch"

outdir = './outdir'

pseudo_dir = "C:/Users/LENOVO/Desktop/QE/deneme/BeO"

/

&SYSTEM

celldm(1) = 5.098

celldm(3) = 3.067

degauss = 0.01

ecutrho = 700.0

ecutwfc = 70.0

ibrav = 4

nat = 4

ntyp = 2

occupations = "smearing"

smearing = "gaussian"

/

&ELECTRONS

conv_thr = 1.00000e-8

electron_maxstep = 100

mixing_beta = 7.00000e-01

startingpot = "atomic"

startingwfc = "atomic+random"

/

&IONS

ion_dynamics = "bfgs"

/

&CELL

cell_dofree = "all"

cell_dynamics = "bfgs"

/

ATOMIC_SPECIES

Be 9.012 Be.pbe-n-rrkjus_psl.1.0.0.UPF

O 15.999 O.pbe-n-rrkjus_psl.1.0.0.UPF

ATOMIC_POSITIONS {crystal}

Be 0.0000 0.0000 0.0000

Be 0.3333 0.6666 0.5000

O 0.0000 0.0000 0.3780

O 0.3333 0.6666 0.8780

K_POINTS {automatic}

24 24 22 0 0 0