hi all,
how to use lattice command in lammps to create Body-centered Tetragonal (BCT) lattice?
This is an example for aluminum and it should work for any single atom type crystal system. You may need to change the lattice parameter to suit your element. Best of luck.
Suleiman.
# bct input structure construction
units metal
atom_style atomic
boundary p p p
# bct5 unit cell
lattice custom 3.448 &
a1 1.0 0.0 0.0 &
a2 0.0 1.0 0.0 &
a3 0.5 0.5 0.397 &
basis 0.0 0.0 0.0
region box block 0.0 6.0 0.0 6.0 0.0 4.0
create_box 1 box
create_atoms 1 box basis 1 1
pair_style eam/alloy
pair_coeff * * ../../potentials/Al_mishin.eam.alloy Al
fix 1 all nve
thermo 1
timestep 0.005
dump out all atom 10 dump.xyz
write_restart restart.al
run 10
Aluminium is FCC crystal structure. Why to use custom command for making FCC lattice.
If I want to create Sn(Tin) lattice what will be the lattice command?
I am giving the details
I tried this lattice command.
lattice custom 1.0 a1 5.831 0 0 a2 0 5.831 0 a3 2.9155 2.9155 1.591 basis 0.25 0 0.375 basis 0.125 0.375 0 orient x 1 0 0 orient y 0 1 0 orient z 0 0 1
Is this command is correct?
From literatures i got the following:
Crystal Structure: Tetragonal
-
Primitive Vectors:
A1 = a X A2 = a Y A3 = ½ a X + ½ a Y + ½ c Z -
Basis Vectors:
B1 = - 1/8 A1 - 3/8 A2 + 1/4__A3__ = - 1/4 a Y + 1/8 c__Z__ (Sn) (4a) B2 = + 1/8 A1 + 3/8 A2 -1/4__A3__ = + 1/4 a Y - 1/8 c__Z__ (Sn) (4a)
Karthik V
I tried this lattice command.
lattice custom 1.0 a1 5.831 0 0 a2 0 5.831 0 a3 2.9155 2.9155 1.591 basis 0.25 0 0.375 basis 0.125 0.375 0 orient x 1 0 >0 orient y 0 1 0 orient z 0 0 1
Is this command is correct?
Why don’t you create one unit cell with these atoms, dump them to a file
and viz them or examine the coords yourself?
Steve