Hmmm... DFT is a method. It has been used by physicists for the last 40 years to model the solid state. What you put forward in your third paragraph is not qui

Hmmm... DFT is a method. It has been used by physicists for the last 40 years to model the solid state. What you put forward in your third paragraph is not quite right - things are more subtle. What you seem to be suggesting is that we should be free of the Kohn-Sham framework[1,2] or find the exact XC functional. Not surprisingly, the results of calculations depend on how the functionals were constructed. But that doesn't mean "DFT" is bad. DFT's just the method. There is no approximation in DFT. It is in itself exact for the description of the ground state. [1]:https://www.princeton.edu/mae/people/faculty/carter/ecdocs/EAC-107.pdf https://www.princeton.edu/mae/people/faculty/carter/ecdocs/E... [2]: http://scitation.aip.org/content/aip/journal/jcp/127/2/10.1063/1.2747249 http://scitation.aip.org/content/aip/journal/jcp/127/2/10.10...