A question to the lattice command.
If I want to setup a lattice with (112) in y-direction and lateral periodic bc, then I could to it like this:
lattice fcc 1.234 orient x -1 -1 1 orient y 1 1 2 orient z -1 1 0
But: this will lead to strange effects at the lateral boundaries. Then I found out, that the unit cell spacing should be set by
lattice … spacing ||-1 -1 1|| ||1 1 2|| ||-1 1 0||
Only this will lead to the (natural) periodic unit cell.
Now I have two questions:
(1) Do I understand it right, that I have to specify the lattice spacing besides the orientations?
(2) If I am right: Why isn’t the lattice spacing automatically calculated as the norm of the orient vectors? Wouldn’t this be more natural, than xmax-xmin of the simple rotated unit cell?