I am trying to calculate vc-relax of (2,2) Carbon Nanotube in Quantum Espresso. I have simulated it many times but the same error occurred. For your clear understanding, I give relax input file.

&CONTROL

calculation = "vc-relax"

restart_mode = 'from_scratch'

outdir = 'cnt_relax'

pseudo_dir = '/home/user/Desktop/latif/pseudo',

prefix = 'calc_relax' ,

/

&SYSTEM

a = 2.28702e+01

c = 2.46180e+00

degauss = 1.00000e-02

ecutrho = 480

ecutwfc = 40

ibrav = 4

nat = 8

ntyp = 1

occupations = "smearing"

smearing = "gaussian"

/

&ELECTRONS

conv_thr = 1.00000e-04

mixing_beta = 7.00000e-01

startingpot = "atomic"

startingwfc = "atomic+random"

/

&IONS

ion_dynamics = "bfgs"

/

&cell

cell_dynamics = "bfgs",

/

K_POINTS {automatic}

3 3 3 0 0 0

ATOMIC_SPECIES

C 12.01060 C.pbe-rrkjus.UPF

ATOMIC_POSITIONS {angstrom}

C 1.402181 -0.000000 -1.233916

C 0.682146 1.225067 -1.233916

C -0.000000 1.402181 0.000000

C -1.225067 0.682146 0.000000

C -1.402181 -0.000000 -1.233916

C -0.682146 -1.225067 -1.233916

C -0.000000 -1.402181 0.000000

C 1.225067 -0.682146 0.000000