I have a silicon system which I am attempting to orient so that the (111) plane is perpendicular to any of the axes. This is so that I can place a layer of carbon parallel to that plane and study the interaction of the (111) plane with the graphene layer.

Any suggestions on how to do this would be appreciated. I am currently attempting to use this set of commands:

variable t equal sqrt(2)

variable u equal -sqrt(2)

lattice diamond 5.43071 orient x $t -1 1 orient y 0 $t $t orient z $u -1 1

However, I get a “Lattice orient vectors are not orthogonal”, even though they are. Searching the documentation and mailing lists seems to indicate that this is because these values must be integers, although I am not sure how to rotate the system how I want it without using irrational numbers.

Thanks,

-Nick