Abstract
Density-functional approximations for the exchange-correlation energy of a many-electron ground state are highly developed and widely useful. When a paramagnetic current is present, Vignale and Rasolt have extended the Kohn-Sham theorems and presented an additive correction valid to second order in the gauge-invariant vorticity : . Apart from spin-polarization effects, their correction is unambiguous for a generalized gradient approximation (GGA). But for a meta-GGA (MGGA), one needs to know how to go back from the orbital kinetic energy density to ; we show how to do this here. Numerical tests on the degeneracies for open-shell atoms show that current-density corrections reduce the error of GGA from 2 to , and of MGGA from 5 to .
- Received 7 June 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.196403
©2005 American Physical Society