Chance of nuts beating second nuts with same ranks, suits?

[rbnn]

I played an amazing limit hold'em heads-up hand, http://www.pokerhand.org/?1684069 , (already posted to BBV http://forumserver.twoplustwo.com/sh...umber=12897887 ) in which my opponent and I had hole cards of the same ranks and the same suits, and in which the the nuts beat the second nuts.

What is the chance of this happening? That is, in a heads-up game, each pocket has the same suits and same ranks, and one player wins?

What about the chance of this happening where neither pocket is the big slick?

Also, I think this configuration is interesting enough to name it.

I propose the term "chiasmus" for a hand in which each player has the same ranks and suits, and where one player wins at showdown.

Thus, I am asking for the odds of a chiasmus in which nut beats second nut.