We have raised ceilings, going up to the center of our house. Can we
use crown molding at an angle like that? And our style is
contemporary. Do they make crown molding in a contemporary style?


I can't help you with style, contemporary or not. My understanding
of the various "styles" is limited to two categories: Things I like,
and Things I don't like.

But physically, yes, you can put (crown) molding anywhere, it's
just a matter of cobbling together a profile that fits.

If that's a big problem, put picture-molding a few inches down
from the ceiling, and paint the ceiling color down the top of the
wall to meet it.