Can I claim any percentage of the new home buyers credit?

I just bought a home with my parents in Arizona I am not married, but at the time of the purchase I was living in California but since then have changed my primary residence to the new home in Arizona. I still commute to California to work. We are listed on the deed as tenants in common but, I would like to know if I can claim any percentage of the credit considering I did contribute money toward the purchase, or can only my parents claim the whole credit considering they were residents at the time of the purchase? What are the rules regarding this situation?