# DFT algorithm

1. Aug 31, 2010

### Karrar

from my reading to DFT I constructed this algorithm

V ex....>$$\rho$$ ....$$\varphi$$.....SCF....new$$\varphi$$>>>new$$\rho$$ ....energy

what your opinion in this algorithm ... is lost to some thing ?

and i need to some one tell me is density come from wave function or from V-external ?

2. Aug 31, 2010

### alxm

I don't see how that constitutes an algorithm (feel free to prove me wrong by writing an implementation).

Charitably interpreting that as a general statement to the effect of "You can use an SCF-like procedure to calculate the density", then that's true. It's also what everyone's been doing for the last 40 years, solving the Kohn-Sham equations. The difficulty in developing the Roothaan-Hall and Kohn-Sham equations wasn't finding an iterative procedure to solve them. They already knew how to solve eigenvalue problems. The difficulty was reformulating the problem into a generalized eigenvalue problem. You're approaching the problem backwards.

3. Aug 31, 2010

### Karrar

I construct this scheme for understanding DFT not for treatment something ... so I have Problem with density equation ... what the equation that include the Vex with electron density ... this my Problem ... thanks alxm for interest