My Community

Hi Dear vasp user,
I’m trying to optimize the lattice parameters. I'm working hexagonal structure (a=b#c and ß=120). I’wd like to use the cell volume in my POSCAR file instead a,b andc. But my file is not working.

POSCAR:
System=surface1
203.098
2.48 0.0 0.0
0.0 2.48 0.0
0.0 0.0 5.86
DIRECT
0.0 0.0 0.0
0.66 0.33 0.33
0.33 0.66 0.66

I would appreciate if someone tell me why it’s not working.


regards

If you read the poscar.F source code, you will find that you have to put "-V" (where V is your volume) in order to interpret the scaling value as a volume. So if you just add a minus sign in front of 203.098 you will get what you want.

EDIT: Note: You also have to add the number of atoms per species after the three basis vectors to get a correct POSCAR.

Best regards,
/Dan Fors


<span class='smallblacktext'>[ Edited Sat Jul 12 2008, 10:00PM ]</span>