Dear all, I wonder if anyone knows how to vanish the forces acting on atoms in a non-primitive cell. I saw that if I have 1x1x5 cell of Cu(111) (or any other systems), the x-y components of forces are zero but when I make 2x2x5 or other supercell, these forces becomes non-zero. Of course, these values are quite small. I used lot of significant digits for coordinates and cell parameters but they do not help.
Many thanks. ---------------------------------------------------- Duy Le Postdoctoral Associate Department of Physics University of Central Florida. Website: http://www.physics.ucf.edu/~dle
