Rotate center 90 degrees on 4x4

[AnTHRaXX]

I am trying to solve a 4x4x4 hexagonal dipyramid and keep ending with one center group that needs to be rotated 90 degrees to complete. Does anyone know an algorithm for a single center rotation on a 4x4x4?

 

[qqwref]

You can't do that without swapping other pieces. However, if you can find two centers or two corners that look the same, then you can do it. (For the same centers, you would solve it with pure center commutators; for the same corners, you could do a T perm to rotate the center by 90 degrees and swap the two corners, and then fix the edges with commutators.)

 

[Matthew3075]

The OLL parity algorithm

 

[qqwref]

The OLL parity algorithm

Actually, that rotates the top center by 180 degrees. (And causes OLL parity.) Nice try though.