There is no operation that
will interchange these elements. Primes designate C2 axes perpendicular to an even principal
axis. The C ^ 42 operation associated with the four-fold axis is called C ^ 2. You might be surprised
to find that a C4 axis and one perpendicular C2´ axis generate the remaining three "primed" twofold
axes. Action of C ^
4 on one C2´ axis generates the other C2´ axis. With the application of C ^
4
or C ^
2 no new axes are generated; however, consider the product of operators C ^
4C ^
2´ acting on
the point (x,y,z).