It's AXΣ Amy, Alpha Chi Sigma

And it is a National Coed Professional Chemistry Fraternity. It is really rather cool, they have a number of highly distinguished members including Linus Pauling (2 nobel Prizes, Pauling Exclusion Principle etc.). Don't worry, they don't have a Frat house or anything like that. They are not a social frat and most of them are nerds like me or Chem. Engineers so...yeah (you need 16 chem credits total to get in).