Local asymptotic gradient corrections to the energy functional of an electron gas

摘要

Gradient corrections to the energy functional for an electron gas are reconsidered. By interpreting these gradient corrections as terms in an asymptotic series, locally at each point in space, an asymptotic summation procedure is suggested. The new local asymptotic summation improves upon the conventional use of the gradient corrections in several respects: (1) The divergence of higherhyphen;order terms is eliminated. (2) The errors in kinetic energy calculated for atoms are reduced by a factor of 3 to 10. (3) The interaction energies of some diatomic systems are qualitatively improved.