Hello all,
I am trying to use LAMMPS to simulate Stillinger Weber Silicon. I have put my input file below. I see, my system seems to be melting below the Melting point. Can anybody please help me in recognizing my mistake.
------Input File-----
units real
dimension 3
atom_style atomic
lattice fcc 5
region box block 0 10 0 10 0 10
create_box 1 box
create_atoms 1 box
mass 1 1.0
velocity all create 1690 41211 mom yes rot yes dist gaussian
pair_style sw
pair_coeff * * si.sw Si
neighbor 0.63 bin
neigh_modify delay 10
timestep 0.3830
run_style verlet
fix 1 all npt 1690 1690 500 xyz 0.0 0.0 200.0
thermo_style custom temp etotal vol press enthalpy
thermo 5
dump 1 all custom 100 ./data/Si_data.out tag type x y z
run 1000
Syam,
May you be using the wrong epsilon in the potential? Check that epsilon=50 kcal/mol.
I think you may be using the parameter file that comes with lammps, that is for metal units (eV)
vale
Hello Valeria,
Thanks for the reply… I am bit new to LAMMPS…
I am using si.sw which contains the following
Si Si Si 2.1683 2.0951 1.80 21.0 1.20 -0.333333333333
7.049556277 0.6022245584 4.0 0.0 0.0
Here epsilon is 2.1683 eV. Should I be changing this value.
Regards
Vishwas
Vishwas,
Yes, if you use “units real” you must change the first parameter to 50 (conversion of 2.1683eV to kcal/mol).
All other parameters remain the same.
vale
Dear Dr. Valeria,
Thanks for your reply on this conversion. Now i am doing the same. once i finish it i will get back to you with my result.
Syam.