[silimay]

I am confused about how there are 6 C4 axis in a cube or in an octahedral point group.  I was looking at SH6 specifically.  I can find 3 C4 axes (one for each axis of the molecule) and thus 3 C4^2 axes.  I can find 6 C2 axes.  But on the character table I am missing 3 C4 axes.

[frenchy]

In SH6, all the "branches" are the same so if you take each one individually and rotate the molecule on the axis of that "branch",you should see that you can turn it 4times by 90 degrees and have the exact same molecule. Using a model for this kind of things usually helps as you get more practice you'll be able to do it in your head.