Dear Lammps Users,
I am trying to simulate BATiO3 Mode 1 Fracture in Lammps. For doing the test I want to have a non periodic boundary condition in y direction. I tried to use KSpace_style msm for doing that but the simulation is not running in this setup.
I would really appreciate if you can help me on simulating Batio3. Is there anyway to implement non-periodic with buckingham potential and kspace? In the Lammps doc, I have seen that I need to use buck/coul/msm with kspace_style msm. It works with boundary p p p, but as soon as I changed it to p s p it is not running. Saying an error code : Out of range atoms - cannot compute MSM.
I am attaching the input script and the log file.
I really appreciate your help on this.
Regards
A R Nazmus Sakib
PhD Candidate
Dept. of Mechanical Engineering
University of Texas at Arlington
Arlington, Texas 76019
in.cap (1.34 KB)
log.lammps (3.6 KB)
testlammps.24931 (2.5 KB)
Stan can advise, but out-of-range atoms means you have a bad
model with bad dynamics. Try printing the thermo output every
step, and you may see when it goes bad.
Steve
It cant even start up the simulation once i make the boundary non periodic. But when it is periodic everything runs fine. Below is the input script I used :
barium titanate using buckingham potential mode 1 fracture
units metal
atom_style charge
boundary p s p
#read_data data.cap
#replicate 5 10 2
lattice custom 3.999 &
a1 1.0 0.0 0.0 &
a2 0.0 1.0 0.0 &
a3 0.0 0.0 1.00925231307827 &
basis 0.0 0.0 0.0 &
basis 0.5 0.5 0.0 &
basis 0.5 0.0 0.5 &
basis 0.0 0.5 0.5 &
basis 0.5 0.5 0.5
region box block 0 10 0 20 0 10
create_box 3 box
create_atoms 1 box &
basis 1 1 &
basis 2 2 &
basis 3 3 &
basis 4 3 &
basis 5 3
mass 1 137.327
mass 2 47.867
mass 3 15.9994
#replicate 5 3 2
group Ba type 1
group Ti type 2
group O type 3
It cant even start up the simulation once i make the boundary non periodic.
But when it is periodic everything runs fine. Below is the input script I
used :
two comments:
i wouldn't say that with periodic boundaries "everything runs fine".
your calculation picks up kinetic energy like crazy and thus
indicating a bad geometry or bad potential parameters.
rather than using shrinkwrap boundaries, you can also try fixed
boundaries with some extra buffer space in y direction. that should
work just as well. you will still see the effects from what looks like
a bad geometry.
axel.
Alex,
Thanks. You are right, the model has some anomaly. Atoms were being lost from one side and appeared from the opposite. So when I change the ensemble to nve it is running.
Regards
A R Nazmus Sakib
PhD Candidate
Dept. of Mechanical Engineering
University of Texas at Arlington
Arlington, Texas 76019