# Weighted density approximation

In this approximation the Helmholtz energy function depends on the weighted density, that is: some average of the density.

## See also[edit]

## References[edit]

- O. Gunnarsson, M. Jonson and B. I. Lundqvist "Exchange and correlation in inhomogeneous electron systems", Solid State Communications
**24**pp. 765-768 (1977) - J. A. Alonso and L. A. Girifalco "Nonlocal approximation to the exchange potential and kinetic energy of an inhomogeneous electron gas", Physical Review B '
*17*pp. 3735 - 3743 (1978) - O. Gunnarsson, M. Jonson and B. I. Lundqvist "Descriptions of exchange and correlation effects in inhomogeneous electron systems" Physical Review B
**20**3136 - 3164 (1979)