Journal ArticleDOI
Valence bond description of antiferromagnetic coupling in transition metal dimers
TLDR
In this paper, a single configuration model containing nonorthogonal magnetic orbitals is developed to represent the important features of the antiferromagnetic state of a transition metal dimer.Abstract:
A single configuration model containing nonorthogonal magnetic orbitals is developed to represent the important features of the antiferromagnetic state of a transition metal dimer. A state of mixed spin symmetry and lowered space symmetry is constructed which has both conceptual and practical computational value. Either unrestricted Hartree–Fock theory or spin polarized density functional theory, e.g., Xα theory, can be used to generate the mixed spin state wave function. The most important consequence of the theory is that the Heisenberg exchange coupling constant J can be calculated simply from the energies of the mixed spin state and the highest pure spin multiplet.read more
Citations
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DFT study of the mechanism for methane hydroxylation by soluble methane monooxygenase (sMMO): effects of oxidation state, spin state, and coordination number
TL;DR: Five diiron models of Q that differ in shape, oxidation state, spin state, and coordination number of the two iron centers are studied and Density functional theory (DFT) calculations show that Fe(III)Fe(IV)( μ-O)(μ-OH) is more reactive than Fe( IV)(2) in the oxygen-rich environment and that the reactivity of the active core of sMMO-Q is not enhanced by converting its oxo bridge into a terminal lig
Journal ArticleDOI
Putting error bars on the ab initio theoretical estimates of the magnetic coupling constants: the parent compounds of superconducting cuprates as a case study.
TL;DR: The influence of the basis set size and computational method in the calculation of the magnetic coupling constant J is evaluated using a series of cuprate superconductor parent compounds as a case study.
Journal ArticleDOI
Oxidation of Methanol to Formaldehyde on Silica-Supported Molybdena: Density Functional Theory Study on Models of Mononuclear Sites
TL;DR: In this article, isolated molybdenum centers bearing either one (oxomoly bdenum system) or two (dioxomolybdasilsesquioxanes) terminal oxo ligands are considered.
Journal ArticleDOI
Hybrid Density Functionals Applied to Complex Solid Catalysts: Successes, Limitations, and Prospects
TL;DR: In this paper, the results obtained using two established and related approaches, namely DFT+U and orbital-dependent hybrid density functionals, were compared with semilocal functionals.
Journal ArticleDOI
A comparative synthetic, magnetic and theoretical study of functional M4Cl4 cubane-type Co(II) and Ni(II) complexes
Alessio Ghisolfi,Kirill Yu. Monakhov,Roberto Pattacini,Pierre Braunstein,Xavier López,Coen de Graaf,Coen de Graaf,Manfred Speldrich,Jan van Leusen,Helmut Schilder,Paul Kögerler,Paul Kögerler +11 more
TL;DR: An analysis based on density functional theory (DFT) was performed to explore possible magnetostructural correlations in these compounds and revealed that compound 1 has four positive and two (small) negative J(Co···Co) isotropic interactions leading to a S(HS) = 6 ground state.
References
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Journal ArticleDOI
New Approach to the Theory of Superexchange Interactions
TL;DR: In this article, the theory of indirect exchange in poor conductors is examined from a new viewpoint in which the $d$ (or $f$) shell electrons are placed in wave functions assumed to be exact solutions of the problem of a single $d-electron in the presence of the full diamagnetic lattice.
Journal ArticleDOI
Orbital interactions in metal dimer complexes
TL;DR: In this paper, the effect of geometrical distortions, electronegativity, and variation of substituents on the magnetic interaction in dimeric systems is examined in detail for singly bridged L,M-X-ML, (n = 3, 4, 5); Cu~C16~ and other doubly bridging species where the bridging ligands are halogens, OR, pyridine N-oxides, oxalate, squarate; and the acetate bridged dimers C u ~ (R C 0 0 ) 4.
Journal ArticleDOI
Quantum Theory of Many-Particle Systems. III. Extension of the Hartree-Fock Scheme to Include Degenerate Systems and Correlation Effects
TL;DR: In this paper, it was shown that if the total wave function is approximated by a projection of a single determinant, the description of the system may be reduced to the ordinary Hartree-Fock scheme treating this determinant.
Book ChapterDOI
Scattered-Wave Theory of the Chemical Bond
TL;DR: In the self-consistent field (SCF)-Xα scattered-wave model that is also a first-principle technique, there is no basis set problem because Schrodinger's equation for an Xα potential is numerically integrated as discussed by the authors.