Help

so i want to get the xfx double D 7850 and i have a xfx 450 power supply. my issue is my Psu only has one 6 pin and that card requires 2. i have 3 open molex on my rig and i want to know if its safe to get a molex to 6pin. i would really like to not have to buy another Psu. i heard molex put out the same power as a 6 pin, just different kind of adapter. i also see that some Gpu come with the adapter, so i want to know it its safe.

What i got

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

what i want

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

http://www.newegg.com/Product/Product.aspx?Item=N82E168...