ABC of DFT

DFT is Density functional theory. By using this we can find out many properties. There are so many packages developed based on DFT. Examples are VASP, CASTEP, QUANTUM ESSPRESSO...etc http://www.google.com.sg/#sclient=psy&hl=en&q=basic+of+density+functional+theory&aq=f&aqi=&aql=&oq=&pbx=1&fp=3e7cbec82e7f9171