Dear Lammps users
I’m taking Ag3Sn as the object as my advicer suggested. The MEAM parameters have been found in “MEAM molecular dynamics study of lead free solder
for electronic packaging applications”, while when I modifed the corresponding files with these parameters and tried to study the diffusion character of Ag3Sn in Lammps, it always warns me “lost atoms”, I’m not sure what induced this problem, the MEAM file? The Lammps code? or my atom datafile? I want to seek for your help that where was the problem. here is my files and Lammps code with atom datafile attached. The atom datafile was exported from MS with one Sn embedded in Ag cell.
Ag and Sn in library.meam
‘Ag’ ‘fcc’ 12. 47 107.870
5.89222008 4.456 2.20 6 2.20 4.08 2.85 1.06
1.0 5.54097609 2.45015783 1.28843988 1. 0
‘Sn’ ‘dia’ 4. 50 118.
6.20 6.2 6.0 6.0 6.0 6.483 3.14 1.12
1.0 4.5 6.5 -0.183 1. 0
Ag3Sn.meam
lattce(1,2) = ‘fcc’
Ec(1,2) = 2.83
alpha(1,2) = 6.07
re(1,2) = 2.96
Cmax(1,2,1) = 2.8
Cmax(1,2,2) = 2.8
Cmax(2,2,2) = 2.8
Cmax(1,1,1) = 2.8
Cmax(2,1,2) = 2.8
Cmax(1,1,2) = 2.8
Cmin(1,2,1) = 2.0
Cmin(1,2,2) = 2.0
Cmin(2,2,2) = 0.8
Cmin(1,1,1) = 2.0
Cmin(1,1,2) = 2.0
Cmin(2,1,2) = 2.0
Lammps code:
units metal
boundary p p p
atom_style atomic
variable x index 300
print “--------Temperature=$x K---------”
read_data data2.diffusion
pair_style meam
pair_coeff * * library.meam Ag Sn Ag3Sn.meam Ag Sn
neighbor 0.6 bin
neigh_modify every 5 delay 0 check yes
group gag type 1
min_style cg
minimize 1.0e-3 1.0e-6 10 1000
run 1000
fix 1 all nvt temp $x $x 2.0 drag 0.2
dump 1 all custom 2000 dump_$x.atom id type xs ys zs
thermo 10000
timestep 0.01
compute 6 all msd
fix 2 gag vector 2 c_6[4]
variable diff equal trap(f_2)
thermo_style custom step v_diff
run 100000
clear
next x
jump in.diffusion
Looking forward for your advice!
Sincerely
Jicheng Zhang
data2.diffusion (11.9 KB)