Need help finding downloadable electro-nuclear simulators for Mac OSX

Kyoshin

Hello. I would like help finding downloadable magnetism simulator applications for my Mac, which runs OSX Lion with 10X GPU Mac Pro, so i won't have to worry about system requirements. I really don't care how much they cost, or how much file space they take up, just a full, downloadable simulator capable of representing multiple interacting magnetic forces simultaneously, as well as electric flow generation. Thank you for your help.