Article

Density functional theory in transition-metal chemistry: a self-consistent Hubbard U approach.

Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Physical Review Letters (Impact Factor: 7.73). 10/2006; 97(10):103001. DOI: 10.1103/PhysRevLett.97.103001
Source: PubMed

ABSTRACT Transition-metal centers are the active sites for a broad variety of biological and inorganic chemical reactions. Notwithstanding this central importance, density-functional theory calculations based on generalized-gradient approximations often fail to describe energetics, multiplet structures, reaction barriers, and geometries around the active sites. We suggest here an alternative approach, derived from the Hubbard U correction to solid-state problems, that provides an excellent agreement with correlated-electron quantum chemistry calculations in test cases that range from the ground state of Fe2 and Fe2- to the addition elimination of molecular hydrogen on FeO+. The Hubbard U is determined with a novel self-consistent procedure based on a linear-response approach.

2 Bookmarks
 · 
117 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Photocatalytic production of transportation fuels should be among our long term strategies to achieve energy and environmental sustainability for the planet, but the technology is hampered by a lack of sufficiently efficient catalysts. Although efficiency is ultimately determined by laboratory measurements, theory and computation have become powerful tools for examining underlying mechanisms and guiding avenues of inquiry. In this review, we focus on first principles calculations of transition metal oxide semiconductor photocatalysts. We discuss how theory can be applied to investigate various aspects of a photocatalytic cycle: light absorption, electron/hole transport, band edge alignments of semiconductors, and surface chemistry. Emphasis is placed on identifying accurate models for specific properties and theoretical insights into improving photocatalytic performance.
    Chemical Society Reviews 10/2012; · 24.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Pre-edge features in X-ray absorption spectroscopy contain key information about the lowest excited states and thus on the most interesting physical properties of the system. In transition metal oxides they are particularly structured but extracting physical parameters by comparison with a calculation is not easy due to several computational challenges. By combining core-hole attraction and correlation effects in first principles approach, we calculate Ni K-edge X-ray absorption spectra in NiO. We obtain a striking, parameter-free agreement with experimental data and show that dipolar pre-edge features above the correlation gap are due to non-local excitations largely unaffected by the core-hole. We show that in charge transfer insulators, this property can be used to measure the correlation gap and probe the intrinsic position of the upper-Hubbard band.
    07/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The exact ground-state exchange-correlation functional of Kohn-Sham density functional theory yields the exact transmission through an Anderson junction at zero bias and temperature. The exact impurity charge susceptibility is used to construct the exact exchange-correlation potential. We analyze the successes and limitations of various types of approximations, including smooth and discontinuous functionals of the occupation, as well as symmetry-broken approaches.
    Physical review. B, Condensed matter 01/2012; 85(15). · 3.77 Impact Factor

Full-text

View
6 Downloads
Available from