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Most Cited Journal Articles 2004-Chemistry
Following is a CAS database record representing a highly cited journal article.
CAPLUS COPYRIGHT 2005 ACS on STN
Generalized gradient approxns. (GGA's) seek to improve upon the accuracy of the local-spin-d. (LSD) approxn. in electronic-structure calcns. Perdew and Wang have developed a GGA based on real-space cutoff of the spurious long-range components of the second-order gradient expansion for the exchange-correlation hole. Authors have found that this d. functional performs well in numerical tests for a variety of systems: Total energies of 30 atoms are highly accurate. Ionization energies and electron affinities are improved in a statistical sense, although significant interconfigurational and interterm errors remain. Accurate atomization energies are found for seven hydrocarbon mols., with a rms error per bond of 0.1 eV, compared with 0.7 eV for the LSD approxn. and 2.4 eV for the Hartree-Fock approxn. For atoms and mols., there is a cancellation of error between d. functionals for exchange and correlation, which is most striking whenever the Hartree-Fock result is furthest from expt. The surprising LSD underestimation of the lattice consts. of Li and Na by 3-4% is cor., and the magnetic ground state of solid Fe is restored. The work function, surface energy (neglecting the long-range contribution), and curvature energy of a metallic surface are all slightly reduced in comparison with LSD. Taking account of the pos. long-range contribution, authors find surface and curvature energies in good agreement with exptl. or exact values. Finally, a way is found to visualize and understand the nonlocality of exchange and correlation, its origins, and its phys. effects. Updated 4/9/2007 1:33:07 PM
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