Barrier height not coming right for NEB calculation with lammps

Dear All,
I am estimating activation barrier height for carbon atom diffusion from one octahedral site to other octahedral site for Fe-C system with NEB method in lammps. I am getting barrier height around 0.5 eV whereas, reported barrier height is around 0.85 eV.
Here is my script:

---------- Initialize Simulation ---------------------


units metal
dimension 3
boundary p p p

atom_style atomic
atom_modify map array sort 0 0.0

variable u uloop 20

---------- Create Atomistic Structure ---------------------

lattice bcc 2.855
region box block 0.0 10.0 0 10.0 0 10.0
#create_box 2 box

Create Fe atoms

#create_atoms 1 box

Insert Carbon interstitial

#create_atoms 2 single 5.0 4.5 4.5

read_data initial.carbon

---------- Define Interatomic Potential ---------------------

pair_style eam/fs
pair_coeff * * Fe-C_Hepburn_Ackland.eam.fs Fe C

group carbon type 2
group iron type 1

#write_data initial.carbon

---------- Define Settings ---------------------

compute csym all centro/atom bcc
compute eng all pe/atom
compute eatoms all reduce sum c_eng

compute int_en carbon group/group iron

region surround block 3.5 6.5 3.5 6.5 3.5 6.5
group nebatoms region surround
group nonneb subtract all nebatoms

---------- Run Minimization before displacement---------------------

#minimize 1e-15 1e-15 5000 5000
reset_timestep 0

thermo 100
#thermo_style custom step pe lx ly lz press pxx pyy pzz c_eatoms

timestep 0.001

fix 1 all nve
fix 2 nonneb setforce 0.0 0.0 0.0
fix 3 nebatoms neb 10.0 parallel neigh perp 1.0
dump 1 nebatoms atom 10 dump.neb.$u
dump 2 nonneb atom 10 dump.nonneb.$u

min_style quickmin
neb 1e-15 1e-15 10000 10000 1000 final final.carbon

Please suggest, where am I going wrong.
I am attaching the curve for activation barrier height.


Is the reported barrier height 0.85 eV with the potential you are using?


Yes, it is. I am using Hepburn Ackland Potential.