John P. Perdew
Department of Physics and Quantum Theory Group, Tulane University, New Orleans, Louisiana 70118
Kieron Burke
Department of Chemistry, Rutgers University, Camden, New Jersey 08102
Yue Wang
Department of Biostatistics, School of Public Health, University of North Carolina, Chapel Hill, North Carolina 27599-7400 ~Received 14 February 1996; revised manuscript received 29 July 1996!
Abstract:
We construct a generalized gradient approximation ~GGA! for the density nxc(r,r1u) at position r1u of the exchange-correlation hole surrounding an electron at r, or more precisely for its system and spherical average ^nxc(u)&5(4p)21*dV u N21*d3r n(r)nxc(r,r1u). Starting from the second-order density gradient expansion, which involves the local spin densities n↑(r),n↓(r) and their gradients ¹n↑(r),¹n↓(r), we cut off the spurious large-u contributions to restore those exact conditions on the hole that the local spin density ~LSD! approximation respects. Our GGA hole recovers the Perdew-Wang 1991 and Perdew-Burke-Ernzerhof GGA’s for the exchange-correlation energy, which therefore respect the same powerful hole constraints as LSD. When applied to real systems, our hole model provides a more detailed test of these energy functionals, and also predicts the observable electron-electron structure factor.
To download the article click on the link below:
http://www.chem.uci.edu/~kieron/dftold/pubs/p16533_1.pdf
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