FW: about how to use the tersoff and eam/sf potentials at the the same time

Please keep the list in the loop.

I didn’t say the lines I types were everything you needed. Just

how to use tersoff and eam/fs for different subsets of atoms.

You still need to define the interactions between those 2 subsets
of atoms.

Steve

all lammps,
I used the hybrid pair_style tersoff eam/fs lj/cut 10.0 .while the lammops shows all pair coeffs are not set,my code is as follow.

units metal # 单位为lammps 中的metel类型
boundary p p p # 边界条件
atom_style atomic # 原子模式
#special_bonds fene
region workpiece1 block 0 47.385 0 50 0 45 units box
region workpiece2 block 47.385 47.91 0 50 0 45 units box
region workpiece3 block 47.91 150 0 50 0 45 units box
region workpiece union 3 workpiece1 workpiece2 workpiece3 units box
region grain cone y 177 22.5 2.5 34.50067 40 60 units box
region total union 4 workpiece1 workpiece2 workpiece3 grain units box
#建铁素体
create_box 4 total
mass 1 55.84 #Fe原子
mass 2 12.011 # C 原子
mass 3 10.811 #B原子
mass 4 14.007 #N原子

lattice custom 2.86 a1 1.0 0.0 0.0 &
a2 0.0 1.0 0.0 &
a3 0.0 0.0 1.0 &
basis 0.0 0.0 0.0 &
basis 0.5 0.5 0.5 &
basis 0.0 0.0 0.5 &
basis 0.0 0.5 0.5 &
basis 0.0 0.5 0.0 &
basis 0.5 0.0 0.0 &
basis 0.5 0.5 0.0 &
basis 0.5 0.0 0.5
create_atoms 1 region workpiece1 basis 1 1 basis 2 1 basis 3 2 basis 4 2 basis 5 2 basis 6 2 basis
7 2 basis 8 2 units box
#建奥氏体
lattice custom 3.58 a1 1.0 0.0 0.0 &
a2 0.0 1.0 0.0 &
a3 0.0 0.0 1.0 &
basis 0.0 0.0 0.0 &
basis 0.5 0.5 0.5 &
basis 0.0 0.0 0.5 &
basis 0.0 0.5 0.5 &
basis 0.0 0.5 0.0 &
basis 0.5 0.0 0.0 &
basis 0.5 0.5 0.0 &
basis 0.5 0.0 0.5
create_atoms 1 region workpiece2 basis 1 1 basis 2 2 basis 3 2 basis 4 1 basis 5 2 basis 6 2 basis
7 1 basis 8 1 units box
#建马氏体
lattice custom 3.018 a1 0.943 0.0 0.0 &
a2 0.0 0.943 0.0 &
a3 0.0 0.0 1 &
basis 0.0 0.0 0.0 &
basis 0.5 0.5 0.5 &
basis 0.0 0.0 0.5 &
basis 0.0 0.5 0.5 &
basis 0.0 0.5 0.0 &
basis 0.5 0.0 0.0 &
basis 0.5 0.5 0.0 &
basis 0.5 0.0 0.5
create_atoms 1 region workpiece3 basis 1 1 basis 2 1 basis 3 2 basis 4 2 basis 5 2 basis 6 2 basis
7 2 basis 8 2

lattice diamond 3.615 #CBN砂轮
create_atoms 3 region grain basis 1 4 basis 2 4 basis 3 4 basis 4 4 basis 5 3 basis 6 3 basis 7 3
basis 8 3 units box
group grain region grain
#pair_coeff * * tersoff BNC.tersoff NULL NULL B N
#pair_coeff * * eam/fs Fe-C.eam.fs Fe C NULL NULL
pair_style hybrid eam/fs tersoff lj/cut 10.0
pair_coeff * * eam/fs Fe_mm.eam.fs Fe NULL NULL NULL #Fe-Fe
pair_coeff 1 2 lj/cut 0.00759200 3.5 9.7625 #Fe-C
pair_coeff * * tersoff BNC.tersoff NULL NULL B N #B-N
pair_coeff 2 4 lj/cut 0.004068 3.367 #N-C
pair_coeff 2 3 lj/cut 0.003311 3.411 #B-C
pair_coeff 2 2 lj/cut 0.00284 3.4 #C-C
neighbor 6 bin
neigh_modify every 1 delay 5 check yes
#bond_style harmonic
#bond_coeff 1 80.0 2.0
run 0 # 运行 0 步,仅为启动 lammps 的热力学数据计算

how can I write the pair function correctly?

College of Mechanical Engineering, Donghua University

Room 3034, academy building 4, 2999 North Renmin Road, Songjiang District

Shanghai, 201620, China

Tel: 86-159-0160-8286

Email: [email protected]…8…

all lammps,
I used the hybrid pair_style tersoff eam/fs lj/cut 10.0 .while the lammops
shows all pair coeffs are not set,my code is as follow.

units metal # 单位为lammps 中的metel类型
boundary p p p # 边界条件
atom_style atomic # 原子模式
#special_bonds fene
region workpiece1 block 0 47.385 0 50 0 45 units box
region workpiece2 block 47.385 47.91 0 50 0 45 units box
region workpiece3 block 47.91 150 0 50 0 45 units box
region workpiece union 3 workpiece1 workpiece2 workpiece3 units box
region grain cone y 177 22.5 2.5 34.50067 40 60 units box
region total union 4 workpiece1 workpiece2 workpiece3 grain
units box
#建铁素体
create_box 4 total
mass 1 55.84 #Fe原子
mass 2 12.011 # C 原子
mass 3 10.811 #B原子
mass 4 14.007 #N原子

lattice custom 2.86 a1 1.0 0.0 0.0 &
                         a2 0.0 1.0 0.0 &
                         a3 0.0 0.0 1.0 &
                         basis 0.0 0.0 0.0 &
                         basis 0.5 0.5 0.5 &
                         basis 0.0 0.0 0.5 &
                         basis 0.0 0.5 0.5 &
                         basis 0.0 0.5 0.0 &
                         basis 0.5 0.0 0.0 &
                         basis 0.5 0.5 0.0 &
                         basis 0.5 0.0 0.5
create_atoms 1 region workpiece1 basis 1 1 basis 2 1 basis 3 2
basis 4 2 basis 5 2 basis 6 2 basis
7 2 basis 8 2 units box
#建奥氏体
lattice custom 3.58 a1 1.0 0.0 0.0 &
                         a2 0.0 1.0 0.0 &
                         a3 0.0 0.0 1.0 &
                         basis 0.0 0.0 0.0 &
                         basis 0.5 0.5 0.5 &
                         basis 0.0 0.0 0.5 &
                         basis 0.0 0.5 0.5 &
                         basis 0.0 0.5 0.0 &
                         basis 0.5 0.0 0.0 &
                         basis 0.5 0.5 0.0 &
                         basis 0.5 0.0 0.5
create_atoms 1 region workpiece2 basis 1 1 basis 2 2 basis 3 2
basis 4 1 basis 5 2 basis 6 2 basis
7 1 basis 8 1 units box
#建马氏体
lattice custom 3.018 a1 0.943 0.0 0.0 &
                         a2 0.0 0.943 0.0 &
                         a3 0.0 0.0 1 &
                         basis 0.0 0.0 0.0 &
                         basis 0.5 0.5 0.5 &
                         basis 0.0 0.0 0.5 &
                         basis 0.0 0.5 0.5 &
                         basis 0.0 0.5 0.0 &
                         basis 0.5 0.0 0.0 &
                         basis 0.5 0.5 0.0 &
                         basis 0.5 0.0 0.5
create_atoms 1 region workpiece3 basis 1 1 basis 2 1 basis 3 2
basis 4 2 basis 5 2 basis 6 2 basis
7 2 basis 8 2

lattice diamond 3.615 #CBN砂轮
create_atoms 3 region grain basis 1 4 basis 2 4 basis 3 4 basis 4 4
basis 5 3 basis 6 3 basis 7 3
basis 8 3 units box
group grain region grain
#pair_coeff * * tersoff BNC.tersoff NULL NULL B N
#pair_coeff * * eam/fs Fe-C.eam.fs Fe C NULL NULL
pair_style hybrid eam/fs tersoff lj/cut 10.0
pair_coeff * * eam/fs Fe_mm.eam.fs Fe NULL NULL NULL #Fe-Fe
pair_coeff 1 2 lj/cut 0.00759200 3.5 9.7625 #Fe-C
pair_coeff * * tersoff BNC.tersoff NULL NULL B N #B-N
pair_coeff 2 4 lj/cut 0.004068 3.367 #N-C
pair_coeff 2 3 lj/cut 0.003311 3.411 #B-C
pair_coeff 2 2 lj/cut 0.00284 3.4 #C-C

Take out a piece of paper and a pen, and work out the combinatorials.
First pair_coeff command above defines interactions for only type 1-1,
second coeff type 1-2, third coeff 3-3, 3-4, 4-4, fourth to sixth 2-2, 2-3,
2-4. Then what do you still miss?

Ray

[...]

Take out a piece of paper and a pen, and work out the combinatorials. First
pair_coeff command above defines interactions for only type 1-1, second
coeff type 1-2, third coeff 3-3, 3-4, 4-4, fourth to sixth 2-2, 2-3, 2-4.
Then what do you still miss?

... and even more important: build your input in stages. first write
an input only for workpiece1 and see if that works correctly. then add
workpiece2 and so on. that will also allow you to spot other problems
and solve them before they become too complex to be solved all at the
same time.

axel.