Weighted density approximation
In this approximation the free energy depends on the weighted density, that is: some average of the density.
References
- 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)