Hi Lammps users,
I want to use reaxff potential to simulate 2d BCN. When I set dimension 2, bond start to break at the first step of minimization. When I set dimension 3, bond are not break, but after I give the initial velocity 10k, and run NVE, the temperature keep increasing over 1000k. Can anyone help me to check that where I got wrong?
Any help would be appreciated.
Sincerely,
Peng
Here is my dimension 3 input script
Initialization
units real
processors 2 2 2
variable
variable b equal 4.26
variable a equal $b*sqrt(3.0)
variable 1_3 equal 1.0/3.0
variable 2_3 equal 2.0/3.0
variable 5_6 equal 5.0/6.0
variable 1_6 equal 1.0/6.0
Setup Box
dimension 3
boundary p p p
atom_style charge
lattice custom 1.0 &
a1 $a 0.0 0.0 &
a2 0.0 $b 0.0 &
a3 0.0 0.0 10.0 &
basis 0.0 0.0 0.0 &
basis ${1_3} 0.0 0.0 &
basis ${2_3} 0.0 0.0 &
basis 0.0 ${2_3} 0.0 &
basis {1_6} {1_6} 0.0 &
basis 0.5 ${1_6} 0.0 &
basis {5_6} {1_6} 0.0 &
basis ${1_6} 0.5 0.0 &
basis 0.5 0.5 0.0 &
basis ${5_6} 0.5 0.0 &
basis {1_3} {2_3} 0.0 &
basis {2_3} {2_3} 0.0 &
region box block 0 10 0 10 -0.25 0.25
create_box 3 box
create_atoms 1 box &
basis 2 2 &
basis 3 3 &
basis 4 2 &
basis 5 3 &
basis 7 2 &
basis 8 3 &
basis 9 2 &
basis 12 3 &
group B type 1
group N type 2
group C type 3
mass 1 10.811
mass 2 14.0067
mass 3 12.0107
Settings
pair_style reax/c NULL
pair_coeff * * ffield.reax.new B N C
fix 1 all qeq/reax 1 0.0 10.0 1.0e-6 reax/c
compute reax all pair reax/c
timestep 0.01
thermo 1
thermo_style custom step temp press pe ke etotal vol density epair lx ly lz
dump 99 all custom 1 dump.reax.atom id type mass xs ys zs
Minimization
min_style cg
minimize 1.0e-10 1.0e-10 1000000 1000000
Heating Stage
velocity all create 10.0 12345 rot yes dist gaussian
fix 2 all nve
run 50000
Here is my dimension 2 input script
Initialization
units real
processors 2 2 2
variable
variable b equal 4.26
variable a equal $b*sqrt(3.0)
variable 1_3 equal 1.0/3.0
variable 2_3 equal 2.0/3.0
variable 5_6 equal 5.0/6.0
variable 1_6 equal 1.0/6.0
Setup Box
dimension 2
boundary p p p
atom_style charge
lattice custom 1.0 &
a1 $a 0.0 0.0 &
a2 0.0 $b 0.0 &
basis 0.0 0.0 0.0 &
basis ${1_3} 0.0 0.0 &
basis ${2_3} 0.0 0.0 &
basis 0.0 ${2_3} 0.0 &
basis {1_6} {1_6} 0.0 &
basis 0.5 ${1_6} 0.0 &
basis {5_6} {1_6} 0.0 &
basis ${1_6} 0.5 0.0 &
basis 0.5 0.5 0.0 &
basis ${5_6} 0.5 0.0 &
basis {1_3} {2_3} 0.0 &
basis {2_3} {2_3} 0.0 &
region box block 0 10 0 10 -0.25 0.25
create_box 3 box
create_atoms 1 box &
basis 2 2 &
basis 3 3 &
basis 4 2 &
basis 5 3 &
basis 7 2 &
basis 8 3 &
basis 9 2 &
basis 12 3 &
group B type 1
group N type 2
group C type 3
mass 1 10.811
mass 2 14.0067
mass 3 12.0107
fix 88 all enforce2d
Settings
pair_style reax/c NULL
pair_coeff * * ffield.reax.new B N C
fix 1 all qeq/reax 1 0.0 10.0 1.0e-6 reax/c
compute reax all pair reax/c
timestep 0.01
thermo 1
thermo_style custom step temp press pe ke etotal vol density epair lx ly lz
dump 99 all custom 1 dump.reax.atom id type mass xs ys zs
Minimization
min_style cg
minimize 1.0e-10 1.0e-10 1000000 1000000
Heating Stage
velocity all create 10.0 12345 rot yes dist gaussian
fix 2 all nve
run 50000