Starting from known identities in density-functional theory, it is shown that for finite electronic systems the density functionals [Formula Presented] and [Formula Presented] can be expanded in terms of powers of the classical moments [Formula Presented] of the electron density, with the expansion coefficients of the two series related in a simple way. For neutral atoms and coupling constant [Formula Presented] two-term universal linear expansions are demonstrated to be reasonably accurate: [Formula Presented] and [Formula Presented] where Z is the atomic number. The factors [Formula Presented] and Z in these formulas are rationalized.
|Number of pages||4|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - jan. 1 1999|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics