Hello everyone,

I have the following lattice vectors:

a1 = 11.8281993900000000 0.0000000000000000 0.0000000000000000

a2 = -5.9140996950000000 10.2435211600000000 0.0000000000000000

a3 = 0.0000000000000000 0.0000000000000000 28.9730530900000000

(as some of you might guess, these come from a VASP POSCAR file)

My problem is turning this, and the positions of the atoms contained

in the DFT simulation, into a LAMMPS friendly format.

From the LAMMPS manual, a non-orthogonal simulation cell can be

defined using the following

a = (xhi-xlo,0,0)

b = (xy,yhi-ylo,0)

c = (xz,yz,zhi-zlo)

It would seem that the only tilt factor I need to consider is xy =

-5.914099695, with all the rest being set to zero. The values in the

lattice vectors make sense, since angle in the slab is 120 deg, which

is consistent with an fcc(111) lattice with a side that has been

aligned with the x-axis. The tilt factor I use, xy, would be the

distance that the upper-left vertex of the xy plane has to the x=0

line (the y-axis, i.e.), placing the origin (xlo, ylo, zlo) = (0, 0,

0).

The box bounds printed in the *dump file are the following, at the top :

-5.9141 11.8282 -5.9141

0 10.2435 0

0 28.9731 0

This makes no sense to me. What is the meaning of these vectors?

This is important to me, because I rely on these vectors for some

unwrapping routines in my scripts.

Thanks,

Camilo