I wouldn't risk it, but I'm nerotic. Mollies can be quite nippy. A Molly will want a couple hiding places, but need a large open area to move around, while betta like hiding places and lots of leaves, plants, nooks and crannys. If you really want to try it, just be sure you can keep a very close eye on them. Give the betta lots of hiding places on the edges of the tank and around the back. Give him places to hide near the surface, but leave the center front of the tank open for the mollys. It'll be easier to keep them from picking on each other if you give them their own spaces.
Oh, and mollies breed like bunnies! If you have a male and a female, expect baby molly fish every 30 days or so.. If you really don't want to keep them, the betta will eat them :/
Bettabettabetta [~] Corrin [~] Mega [~] Rinji [~] Red Robin [~] Jr. [~] Billy [~] Opti
Tidbit [~] Princess [~] Little [~] Spazz [~] Rosie [~] Sakura [~] Cocoa [~] Pylia
So many fish, so little sig room :)
Miko - forever kitten [~] Cain & Tyrael - twin cats [~] Sadie - RN Pitbull; Proud new mother!! 1-21-13
Gwen - Perfect Daughter!