Hi, LAMMPS users:
My model comprises a polymer film & a diamond-like carbon film, where I use hybrid potential: class2 for the polymer & tersoff for the diamond. I use Material Studio to build up the whole model, then convert into Lammps data file (via “msi2lmp” tool) using pcff forcefield. Then I modified the data file via removing all the interaction information (bond, angle, dihedral, improper) in the diamond film, and assign the diamond film with tersoff potential. (some inputs & data file as below).
However, running the simulation, it seems the tersoff potential doesn’t work for the diamond film. The simulation can run on smoothly but the results are totaly messy for the diamond film. Checking some previous mails, it seems that the manybody potential (tersoff, airebo, etc.) not easy to work with class2 as hybrid potential. It there a method to solve the issue?
Many Thanks in advance!
Input file:
Initialization
units real
atom_style full
boundary p p p
Forcefield
hybrid pair coeff
pair_style hybrid lj/class2/coul/cut 10. tersoff
topology style for polymer
bond_style class2
angle_style class2
dihedral_style class2
improper_style class2
read data file
read_data NS.inp
atom style 1-4 for polymer atoms, 5,6 for diamond atoms
LJ pair coeff for polymer atoms
pair_coeff 1 1 lj/class2/coul/cut 0.2400000000 3.5350000000
pair_coeff 1 2 lj/class2/coul/cut 0.1138419958 3.7650166002
pair_coeff 1 3 lj/class2/coul/cut 0.1197998331 3.3633316815
pair_coeff 1 4 lj/class2/coul/cut 0.0692820323 3.2538169893
pair_coeff 1 5 lj/class2/coul/cut 0.1138419958 3.7650166002
pair_coeff 1 6 lj/class2/coul/cut 0.1138419958 3.7650166002
pair_coeff 2 2 lj/class2/coul/cut 0.0540000000 4.0100000000
pair_coeff 2 3 lj/class2/coul/cut 0.0568260504 3.5821781084
pair_coeff 2 4 lj/class2/coul/cut 0.0328633535 3.4655374764
pair_coeff 2 5 lj/class2/coul/cut 0.0540000000 4.0100000000
pair_coeff 2 6 lj/class2/coul/cut 0.0540000000 4.0100000000
pair_coeff 3 3 lj/class2/coul/cut 0.0598000000 3.2000000000
pair_coeff 3 4 lj/class2/coul/cut 0.0345832329 3.0958036113
pair_coeff 3 5 lj/class2/coul/cut 0.0568260504 3.5821781084
pair_coeff 3 6 lj/class2/coul/cut 0.0568260504 3.5821781084
pair_coeff 4 4 lj/class2/coul/cut 0.0200000000 2.9950000000
pair_coeff 4 5 lj/class2/coul/cut 0.0328633535 3.4655374764
pair_coeff 4 6 lj/class2/coul/cut 0.0328633535 3.4655374764
pair_coeff * * tersoff C.tersoff NULL NULL NULL NULL C C # atom style 5 & 6 for the diamond atoms
Parameter of simulation
neighbor 5 bin
neigh_modify every 1 delay 0 check yes page 1000000 one 10000
timestep 0.1
…………
………
Data file (NS.inp):
LAMMPS 2012 data file for Layer: modified
24342 atoms
3650 bonds
6550 angles
6750 dihedrals
3900 impropers
6 atom types
9 bond types
18 angle types
20 dihedral types
12 improper types
0.000000000 92.736500000 xlo xhi
0.000000000 42.801500000 ylo yhi
0.000000000 69.904600000 zlo zhi
Masses
………………………
Bond Coeffs
………
Angle Coeffs
……………
Thanks & Best Regards!
Dai Ling
Scientist
Institue of High Performance Computing, A*STAR
Singapore
Tel: +65-64191428