Density Functional Theory

Density Functional Theory DFT is a reformulation of Hartree-Fock in terms of a joint electron density

  • \rho (x)=\int\psi^2(x,x_2,...,x_N)dx_2...dx_N,

which introduces a new contribution (from Slater determinants) to the total energy named exchange-correlation energy EC(\rho ). The dependence of EC(\rho ) on \rho is unknown and DFT thus relies on predictions of EC based on Hartree-Fock and thus DFT has the same limitations as Hartree-Fock, albeit at (somewhat) smaller computational cost.