0 0 0 a
0 0 1/2 b
0 1/2 0 c
1/2 0 0 d
1/2 1/2 0 e
1/2 0 1/2 f
0 1/2 1/2 g
1/2 1/2 1/2 h
x y z i
-x -y -z i