Dear Ivan, If you take a look at the MPCD ( http://www.cinam.univ-mrs.fr/mpcd/ ) and search for Fab it brings up 172 crystallization conditions. The names should help you narrow down, which conditions are of a complex. Hopefully, you can use those conditions to help you decide, which direction you want to head.
Spoiler - Fabs like ammonium sulfate. Take Care, Sean P212121 http://store.p212121.com/