Frank,
OK I was able to look at this sooner than I expected (can't sleep!). Thank you *so* much. It makes perfect sense now!! Even though I don't understand their basis completely, those formulas for amp/phase really help. I can't wait to do some insane stuff, and of course I will post my results to the list.
On a second note, I don't understand why basic FFT is thought of as being "advanced". I think other things are much more difficult to understand! Let's do as Kyle suggested and get this on the community site somewhere maybe with some images of arrays to clarify? Vasp was such a help to me because I could look at the arrays after the calcs were done.
Thanks again - I owe you a beer if we ever meet.
K