Atomic correlation energies and the generalized gradient approximation

Original · EN

Careful extrapolation of atomic correlation energies suggests that Ec tends to -AZZ + BZ as Z tends to infinity, where Z is the atomic number, A is known, and B is about 38 milliHartrees. The coefficients roughly agree with those of the high-density limit of the real-space construction of the generalized gradient approximation. An asymptotic coefficient, missed by previous derivations, is included in a revised approximation. The exchange is also corrected, reducing atomic errors considerably.