Structures and electronic phases of the bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) clusters and κ-(BEDT-TTF) salts: A theoretical study based on <i>ab initio</i> molecular orbital methods

Imamura, Yutaka; Ten‐no, Seiichiro; Yonemitsu, Kenji; Tanimura, Yoshitaka

doi:10.1063/1.479894

Cited by 33 publications

(23 citation statements)

References 37 publications

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“…6͒ where significant insight has been gained from parametrizing effective low-energy Hamiltonians from DFT calculations on a single ͑or a few͒ molecules. There have been some pioneering efforts [7][8][9][10][11] to apply this approach to ET salts, but no systematic study of the wide range of ET salts is known to synthetic chemistry. Many other families of organic charge transfer salts based on other donor and even acceptor molecules are also known to show strong correlation effects.…”

Section: Introductionmentioning

confidence: 99%

Toward the parametrization of the Hubbard model for salts of bis(ethylenedithio)tetrathiafulvalene: A density functional study of isolated molecules

Scriven

Powell

2009

The Journal of Chemical Physics

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Articles you may be interested in A self-consistent Hubbard U density-functional theory approach to the addition-elimination reactions of hydrocarbons on bare FeO + J. Chem. Phys. 129, 134314 (2008) argue that this variation in the site energy plays a key role in understanding the role of disorder in bis͑ethylenedithio͒tetrathiafulvalene salts. We explain the differences between the ␤ L and ␤ H phases of ͑BEDT-TTF͒ 2 I 3 on the basis of calculations of the effects of disorder.

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Section: Introductionmentioning

confidence: 99%

Toward the parametrization of the Hubbard model for salts of bis(ethylenedithio)tetrathiafulvalene: A density functional study of isolated molecules

Scriven

Powell

2009

The Journal of Chemical Physics

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“…As in the quasi-1D compounds in § 2, U is believed to be of the order of 1 eV in the ET compounds as well, while, again, the actual values for V ij /U estimated as 0.2 ∼ 0.7 [119][120][121] are too ambiguous for quantitative arguments. Typical values for |t ij | in the ET materials estimated by the extended Hückel method range around 0.1 ∼ 0.25 eV.…”

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confidence: 99%

Theoretical Aspects of Charge Ordering in Molecular Conductors

et al. 2006

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Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in: El acceso a la versión del editor puede requerir la suscripción del recurso Access to the published version may require subscription (Received February 4, 2008) Theoretical studies on charge ordering phenomena in quarter-filled molecular (organic) conductors are reviewed. Extended Hubbard models including not only the on-site but also the inter-site Coulomb repulsion are constructed in a straightforward way from the crystal structures, which serve for individual study on each material as well as for their systematic understandings. In general the inter-site Coulomb interaction stabilizes Wigner crystal-type charge ordered states, where the charge localizes in an arranged manner avoiding each other, and can drive the system insulating. The variety in the lattice structures, represented by anisotropic networks in not only the electron hopping but also in the inter-site Coulomb repulsion, brings about diverse problems in low-dimensional strongly correlated systems. Competitions and/or co-existences between the charge ordered state and other states are discussed, such as metal, superconductor, and the dimer-type Mott insulating state which is another typical insulating state in molecular conductors. Interplay with magnetism, e.g., antiferromagnetic state and spin gapped state for example due to the spin-Peierls transition, is considered as well. Distinct situations are pointed out: influences of the coupling to the lattice degree of freedom and effects of geometrical frustration which exists in many molecular crystals. Some related topics, such as charge order in transition metal oxides and its role in new molecular conductors, are briefly remarked.

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“…The first one determines the energy scale and the latter determines the strength of the electron correlations. Previously these model parameters were determined by using the excitation energy [6,8], the orbital energies [6,8], or the calculation result of fragments of the system [9]. According to the strategy proposed in the previous section, we determine the parameters by using the UHF solutions.…”

Section: Determination Of Two-site Hubbard Model Parametersmentioning

confidence: 99%

“…Fortunelli et al [6] determined the parameters so that the model reproduces ab initio energy differences, which were estimated with the orbital energies of restricted Hartree-Fock (RHF) solutions. Imamura et al [8] estimated the parameters by assuming the Hubbard model sites to be the localized orbitals of RHF solutions. Yamaguchi and co-workers [9] proposed a fitting scheme using UHF solutions and the empirical relationship between the overlap integral and the parameters.…”

Section: Introductionmentioning

confidence: 99%

Determination of the Hubbard model parameters by using the unrestricted Hartree–Fock solutions, and improvement of their energies

Yamaki

Yasuda

Yamaguchi

2005

Int J of Quantum Chemistry

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ABSTRACT:A strategy is proposed to determine parameters in model Hamiltonians from the difference of the density matrices calculated by ab initio methods. As an example, the parameters of the two-site Hubbard model are determined. The parameters t and U are explicitly expressed in terms of the energy difference and the difference of the expectation values of the spin operator ͗S 2 ͘ between two unrestricted Hartree-Fock (UHF) solutions. By using this relation and the exact energy formulas of the model Hamiltonian the energies of the ground and excited states of the ab initio Hamiltonian are estimated. This energy estimation scheme is applied to H 2 and Li 2 molecules and the results are in reasonable agreement with those of the full configuration-interaction method. The errors of our estimation are also discussed and evaluated by using a modified Hubbard model.

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Structures and electronic phases of the bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) clusters and κ-(BEDT-TTF) salts: A theoretical study based on ab initio molecular orbital methods

Abstract: Articles you may be interested inToward the parametrization of the Hubbard model for salts of bis(ethylenedithio)tetrathiafulvalene: A density functional study of isolated molecules

Cited by 33 publications

References 37 publications

Toward the parametrization of the Hubbard model for salts of bis(ethylenedithio)tetrathiafulvalene: A density functional study of isolated molecules

Toward the parametrization of the Hubbard model for salts of bis(ethylenedithio)tetrathiafulvalene: A density functional study of isolated molecules

Theoretical Aspects of Charge Ordering in Molecular Conductors

Determination of the Hubbard model parameters by using the unrestricted Hartree–Fock solutions, and improvement of their energies

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