lattice, custom command

LAMMPS LAMMPS Mailing List Mirror
1

Dear lammps users
i am trying to build graphene with lattice custom command, here is part of my input:

lattice custom 2.501851166 a1 1.0 0.0 0.0 a2 0.5 0.8660254037844386 0.0 basis 0.0 0.0 0.0 &
basis 0.5 0.28867513459481287 0.0
region box block 0 1 0 1 -10 10
create_box 1 box

region sheet block 0 1 0 1 -0.1 0.1
create_atoms 1 region sheet

i expect that coordination of basis atoms multiply by lattice constant, but in my dumpfile coordination are not what i expected:
ITEM: TIMESTEP
0
ITEM: NUMBER OF ATOMS
3
ITEM: BOX BOUNDS pp pp pp
0 3.75278
0 2.16667
-25.0185 25.0185
ITEM: ATOMS id type x y z
1 1 0 0 0
2 1 1.61204 0.625463 0

in fact coordination of second basis atom is not multipled by lattice constant .am i right? if not can you tell me what is this factor and get me some information to solve this problem?

Best Regard.

2

Dear lammps users
i am trying to build graphene with lattice custom command, here is part of my input:

lattice custom 2.501851166 a1 1.0 0.0 0.0 a2 0.5 0.8660254037844386 0.0 basis 0.0 0.0 0.0 &
basis 0.5 0.28867513459481287 0.0
region box block 0 1 0 1 -10 10
create_box 1 box

region sheet block 0 1 0 1 -0.1 0.1
create_atoms 1 region sheet

i expect that coordination of basis atoms multiply by lattice constant, but in my dumpfile coordination are not what i expected:
ITEM: TIMESTEP
0
ITEM: NUMBER OF ATOMS
3
ITEM: BOX BOUNDS pp pp pp
0 3.75278
0 2.16667
-25.0185 25.0185
ITEM: ATOMS id type x y z
1 1 0 0 0
2 1 1.61204 0.625463 0

in fact coordination of second basis atom is not multipled by lattice constant .am i right? if not can you tell me what is this factor and get me some information to solve this problem?

What are your units?

3

i work in real unit , with reax/c pair_style.

4

The x-coord of your 2nd basis atom is

x = lc * (0.5 * a1x + 0.288a2x + 0.0a3x)

where lc = 2.50…

When you define a non-orthogonal unit cell, you
have to multiply the basis vector by all 3 cell vectors.

I.e. all 3 cell vectors can have a contribution to the x coordinate.

Steve

5

Dear steve
thanks for your reply, i apply it and my problem solved.

Best Regard.