melting point deflection

Hi to All,

I am trying to calculate melting point of bulk nickel with eam
potential.after some run with different temperature, the diagram of
potential energy-temperature show a nice energy jump.but the
transition temperature shows a big
deflection with experiment data, the result of simulation shows
melting point is greater than experiment about 200 degree. I repeated
my calculation , (with some change in code, with
change in number of atom) but the all of results show same deflection.
please help me.

units metal
atom_style atomic
boundary p p p
lattice fcc 3.52
region box block 0 5 0 5 0 5
create_box 1 box
create_atoms 1 box
mass 1 58.710
velocity all create 1700 493389 dist gaussian
pair_style eam
pair_coeff * * Ni_u3.eam
neighbor 0.5 bin
neigh_modify every 5 delay 0 check no
thermo_pe all pe
fix id all npt temp 1700.0 1700.0 10 iso 1.0 1.0 1000
dump id all atom 1000 dump.melt
dump_modify id scale no
thermo_style custom step temp press vol pe ke etotal
thermo 100
timestep 0.01
run 500000

Hi to All,

I am trying to calculate melting point of bulk nickel with eam
potential.after some run with different temperature, the diagram of
potential energy-temperature show a nice energy jump.but the
transition temperature shows a big
deflection with experiment data, the result of simulation shows
melting point is greater than experiment about 200 degree. I repeated
my calculation , (with some change in code, with
change in number of atom) but the all of results show same deflection.
please help me.

please help yourself to reading previous discussions
on this very subject (melting point determination) in the
mailing list archives and read up on kinetic effects on
thermodynamic properties as well as the hysteresis
for melting and freezing (have you checked the inverse
process? i.e. freezing a liquid system?) in finite (= anything
that you can manage with a computer simulation)
size systems.

cheers,
    axel.