fix atom/swap

Deal all,

I am using fix atom/swap command, but I get different results when I run the same script with different versions. When I used the lammps-22Aug18 , I think the results were reasonable. But when I used the lammps-7Aug19, most of the Pb atoms were replaced by Al atoms, there is same problem??

Any help would be appreciated.

Best,
Hongtao Liang

my input script:

units metal

atom_style atomic

lattice fcc 4.9095

region YYr1 block 0.0 10.0 0.0 10.0 0.0 10.0 units lattice

create_box 2 YYr1

create_atoms 2 region YYr1

pair_style eam/alloy

pair_coeff * * AlPb.eam.alloy Al Pb

neighbor 2.0 bin

neigh_modify every 1 delay 0 check yes

atom_modify sort 0 0.0

thermo 1000

thermo_style custom step temp pe etotal press vol pxx pyy pzz enthalpy lx xlo xhi ly ylo yhi lz zlo zhi

thermo_modify flush yes line one

compute YYc1 all pe/atom

variable YYv0 equal etotal

variable YYv1 equal vol

variable YYv2 equal lx

variable YYv3 equal ly

variable YYv4 equal lz

fix YYo1 all ave/time 1 1000 1000 c_thermo_temp v_YYv0 v_YYv1 v_YYv2 v_YYv3 v_YYv4 file 06.Ave

timestep 0.001

velocity all create 1000.0 12345 dist gaussian mom yes rot yes

fix YYMD00 all momentum 1 linear 1 1 1

dump dump1 all custom 1000 04.Trajectory.xyz id type x y z

fix YYMD all npt temp 1000.0 750.0 0.1 iso 1.0 1.0 1.0

run 100000

unfix YYMD

fix YYMD all nvt temp 750.0 750.0 0.1 #iso 1.0 1.0 1.0

fix YYMD1 all atom/swap 1 1 2223456 750 ke yes semi-grand yes types 1 2 mu 1.70 0.00

run 500000

Deal all,

I am using fix atom/swap command, but I get different results when I run the same script with different versions. When I used the lammps-22Aug18 , I think the results were reasonable. But when I used the lammps-7Aug19, most of the Pb atoms were replaced by Al atoms, there is same problem??

there was a sign error in the mu parameter that was corrected after the 22 August 2018 release.

please see the backward compatibility note for version 10 October 2018 at https://lammps.sandia.gov/bug2018.html
and https://github.com/lammps/lammps/pull/1143 for more details.

axel.