Dear Steve,
I am using LAMMPS for oxide systems, e.g. La-Ti-O systems, in literature they published the parameters as:
La-O: Aij=1159.23 eV rhoij=0.351884 Angstrom qi=2.76e
Ti-O: Aij=14567.4 eV rhoij=0.197584 Angstrom qi=2.36e
O-O: Aij=6249.17 eV rhoij=0.231472 Angstrom qi=-1.4e
Aij=0 for cation-cation interactions.
The potential part in LAMMPS script is as:
…
units metal
boundary p p p
atom_style charge
neighbor 2 bin
neigh_modify delay 5
read_data LaTiO101010.lammps
mass 1 15.999
mass 2 47.867
mass 3 138.9
group oxygen type 1
group Titanium type 2
group Latium type 3
pair_style buck/coul/cut 12 15
pair_coeff 2 * 0.0 10 0 15
pair_coeff 3 * 0.0 10 0 15
pair_coeff 1 1 6249.17 0.231472 0 12
pair_coeff 1 2 14567.4 0.197584 0 12
pair_coeff 1 3 1159.23 0.351884 0 12
#dielectric 0.2
set group oxygen charge -1.4
set group Titanium charge +2.36
set group Latium charge +2.76
…
After relaxation, it can not get the equilibrium lattice parameter and stress free.
Could you please give some suggestion if the potential format above is correct for LAMMPS?
Thanks,
Ruifeng