Radeon 6950 compatibility help

I purchased a Radeon 6950 and a new 700w power supply for my pc, the card will be arriving later today and I just found out it requires the 2 pcie 6 pin slots for aux. power supply. My MOBO is a MSi H55M-E23, it does not have these slots. My question is, can I used 2x molex adapters to power the card safely without harming anything, the molex I do have available. I am new to learning about computer building so all help is appreciated   Thank you