Quote Originally Posted by rett2 View Post
Zinc? You think that's zinc? Zinc is an hcp metal. Do you think that looks like a single-species trigonal unit cell? What axis are you looking along?

It’s cubic viewed along [111] the threefold symmetry axis. This is the zinc-blende structure, a cubic unit cell of zinc sulphide. It's also one of the most basic reference structures. It's probably the threefold symmetry that threw you off (three... hexagonal.... easy mistake to make). Happens to sophmores typically.
congratulations

is there a prize for stumping SoCo?