0 0 0 a
1/2 0 1/2 a
0 1/2 1/2 a
1/2 1/2 0 a
0 0 1/2 b
1/2 0 0 b
0 1/2 0 b
1/2 1/2 1/2 b
x y z c
-x+1/2 -y z+1/2 c
-x y+1/2 -z+1/2 c
x+1/2 -y+1/2 -z c
-x -y -z c
x+1/2 y -z+1/2 c
x -y+1/2 z+1/2 c
-x+1/2 y+1/2 z c