First-principles study of the neutral molecular metal<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">Ni</mml:mi><mml:mo>(</mml:mo><mml:mi mathvariant="normal">tmdt</mml:mi><mml:mrow><mml:msub><mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Rovira, Carme; Novoa, Juan J.; Mozos, José-Luís; Ordejón, Pablo; Canadell, Enric

doi:10.1103/physrevb.65.081104

Cited by 60 publications

(68 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The metallic state here is due to the overlap of HOMO and LUMO bands as designed (which is a surprising fact!). The existence of Fermi surfaces has been experimentally confirmed by dHvA [95] whose oscillations are in agreement with results of band structure calculations, first by tight-binding approximation [93] and later by more detailed first principle calculations [96][97][98] agreeing with each other. It is to be noted that a large positive and isotropic magneto-resistance has been observed in this system [99], whose origin is not identified.…”

Section: Single Component Molecular Metalssupporting

confidence: 75%

Achievements and Challenges in Molecular Conductors

Fukuyama¹

2012

Crystals

View full text Add to dashboard Cite

Molecular solids are generally highly insulating. The creation of conducting molecular solids proved to be a major scientific challenge. As in the case of Si technology, the challenge started as impurity doping in band insulators and then developed into highly doped polymers, which are not crystalline. More conducting materials in crystalline forms have been realized in charge transfer (CT) complexes with two different kinds of molecules, where electrons are transferred between them in solids. In such CT complexes, not only conducting, but also even superconducting systems were achieved in 1980 and today more than 100 different superconductors are known. The most remarkable achievement in this direction was the realization of a truly metallic state in molecular solids based on a single kind of molecule. These are called single component molecular metals (SCMM) and consist of a rich variety of electronic properties. In these conducting molecular solids, CT and SCMM, many interesting electronic properties resulting from mutual Coulomb interactions and electron-phonon interactions have been explored so far, and these will be reviewed briefly in this article from a theoretical viewpoint. Challenges to come, based on these achievements, are also discussed at the end of this review.

show abstract

Section: Single Component Molecular Metalssupporting

confidence: 75%

Achievements and Challenges in Molecular Conductors

Fukuyama¹

2012

Crystals

View full text Add to dashboard Cite

show abstract

“…3 The observation of de Haasvan Alphen oscillations at very high magnetic fields and low temperatures as well as ab initio band structure calculations proved the existence of the three-dimensional (3D) Fermi surfaces (FSs). 4,5 To date, various single-component molecular metals including a series of isostructural [M(tmdt) 2 ] (M = Ni, Cu, Pd, Au, and Pt) systems have been reported. 6 The high controllability of the electronic band structure achieved by exchanging the central metal atom (M) for another transition metal is an important characteristic of the single-component molecular conductor.…”

mentioning

confidence: 99%

Single-component Layered Molecular Conductor, [Au(ptdt)2]

et al. 2012

View full text Add to dashboard Cite

A single-component layered molecular conductor, [Au(ptdt) 2 ] (ptdt: propylenedithiotetrathiafulvalenedithiolate) was prepared. Unlike the single-component molecular metal, [Au(tmdt) 2 ] (tmdt: trimethylenetetrathiafulvalenedithiolate) exhibiting three-dimensional compact molecular packing and antiferromagnetic transition at 110 K, the compressed pellet of the microcrystals of [Au(ptdt) 2 ] exhibited fairly high conductivity and small temperature-independent paramagnetic susceptibility.In 1999, the crystal structure and electrical properties of a single-component molecular conductor, [Ni(ptdt) 2 ] (Chart 1), were reported.1 Although [Ni(ptdt) 2 ] did not exhibit metallic properties, it exhibited high conductivity. This high conductivity of the crystal convinced us of the validity of our idea regarding the design of a single-component molecular metal.2 Two years later, the first single-component molecular metal, [Ni(tmdt) 2 ], was realized by using an analogous extended-TTF-type (TTF: tetrathiafulvalene) dithiolate ligand, tmdt.3 The observation of de Haasvan Alphen oscillations at very high magnetic fields and low temperatures as well as ab initio band structure calculations proved the existence of the three-dimensional (3D) Fermi surfaces (FSs). 4,5 To date, various single-component molecular metals including a series of isostructural [M(tmdt) 2 ] (M = Ni, Cu, Pd, Au, and Pt) systems have been reported. 6 The high controllability of the electronic band structure achieved by exchanging the central metal atom (M) for another transition metal is an important characteristic of the single-component molecular conductor. The electronic band structure of [M(tmdt) 2 ] near the Fermi level is determined mainly by three molecular orbitals, namely, sym-L³, asym-L³(d), and pd·(¹) orbitals (Figure 1). 8 The sym-L³ and asym-L³(d) orbitals form 3D stable metal bands in the Ni, Pd, and Pt complexes with an even number of total electrons. On the other hand, the asym-L³(d) orbital becomes the singly occupied molecular orbital (SOMO) of Au(tmdt) 2 with an odd number of total electrons, and [Au(tmdt) 2 ] becomes a magnetic metal exhibiting antiferromagnetic transition at 110 K (in this paper, [M(tmdt) 2 ] and M(tmdt) 2 represent the crystal of a singlecomponent molecular conductor and the constituent molecule, respectively). 9 In the case of [Cu(tmdt) 2 ], pd·(¹) becomes the SOMO and an antiferromagnetic chain coexists with ³ conduction electrons. 10In addition to the frontier molecular orbital properties, the mode of molecular arrangement, which is controllable to a certain extent by the type of ligand (L) used, plays a crucial role in the determination of the band structure of a single-component molecular conductor [M(L) 2 ]. A variety of electronic structures can be realized by using different combinations of M and L. However, the role of L, especially the bulkiness of the terminal alkyl group of L has not been investigated sufficiently. In this work, [Au(ptdt) 2 ] was prepared in order to study the effect of the terminal alk...

show abstract

“…22,23 From DFT-based ab initio calculations for these compounds, several MOs are shown to contribute to the conduction band of the crystal systems. [22][23][24] It has been recognized that the frontier orbitals for these compounds can be decomposed into several moieties, i.e., fragment MOs, and the electronic states have been analyzed using the microscopic tight-binding Hamiltonian based on the fragment MOs. 25 The charge-transfer molecular compound (TTM-TTP)I 3 (Refs.…”

mentioning

confidence: 99%

Ab initio derivation of multi-orbital extended Hubbard model for molecular crystals

Tsuchiizu

Omori

Suzumura

et al. 2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

From configuration interaction (CI) ab initio calculations, we derive an effective two-orbital extended Hubbard model based on the gerade (g) and ungerade (u) molecular orbitals (MOs) of the chargetransfer molecular conductor (TTM-TTP)I-3 and the single-component molecular conductor Au(tmdt)(2)]. First, by focusing on the isolated molecule, we determine the parameters for the model Hamiltonian so as to reproduce the CI Hamiltonian matrix. Next, we extend the analysis to two neighboring molecule pairs in the crystal and we perform similar calculations to evaluate the intermolecular interactions. From the resulting tight-binding parameters, we analyze the band structure to confirm that two bands overlap and mix in together, supporting the multi-band feature. Furthermore, using a fragment decomposition, we derive the effective model based on the fragment MOs and show that the staking TTM-TTP molecules can be described by the zig-zag two-leg ladder with the inter-molecular transfer integral being larger than the intra-fragment transfer integral within the molecule. The inter-site interactions between the fragments follow a Coulomb law, supporting the fragment decomposition strategy. . First, by focusing on the isolated molecule, we determine the parameters for the model Hamiltonian so as to reproduce the CI Hamiltonian matrix. Next, we extend the analysis to two neighboring molecule pairs in the crystal and we perform similar calculations to evaluate the intermolecular interactions. From the resulting tight-binding parameters, we analyze the band structure to confirm that two bands overlap and mix in together, supporting the multi-band feature. Furthermore, using a fragment decomposition, we derive the effective model based on the fragment MOs and show that the staking TTM-TTP molecules can be described by the zig-zag two-leg ladder with the inter-molecular transfer integral being larger than the intra-fragment transfer integral within the molecule. The inter-site interactions between the fragments follow a Coulomb law, supporting the fragment decomposition strategy.

show abstract

First-principles study of the neutral molecular metalNi(tmdt)2

Cited by 60 publications

References 24 publications

Achievements and Challenges in Molecular Conductors

Achievements and Challenges in Molecular Conductors

Single-component Layered Molecular Conductor, [Au(ptdt)2]

Ab initio derivation of multi-orbital extended Hubbard model for molecular crystals

Contact Info

Product

Resources

About