A basic question about unitcell

[jjkim]

I want to make two sizes of face-centered cubic primitive cell.

32 and 108 lattice sites per unit cell..

how can I make it?

<span class='smallblacktext'>[ Edited ]</span>

[forsdan]

Extend the standard unit of a cubic fcc cell with 4 basis atoms into a 2x2x2 and a 3x3x3 unit respectively. This gives you 4*2*2*2 = 32 and 4*3*3*3 = 108 lattice sites per unit cell. You have to by yourself supply all the coordinates to the POSCAR file and adjust the basis vectors of the unit cell accordingly.

Please have a look at the manual for the POSCAR file if any input format is unclear.

Cheers,
/Dan




<span class='smallblacktext'>[ Edited Sun May 16 2010, 11:02AM ]</span>

[jjkim]

Thank you!!^^