Valence instability in a dimer of two-orbital system:: possible charge separation due to 'negative U' effect

被引：38

作者：

Tamura, M ^{[1
]}

Kato, R ^{[1
]}

机构：

[1] RIKEN, CREST, JST, Condensed Mol Mat Lab, Wako, Saitama 3510198, Japan

来源：

CHEMICAL PHYSICS LETTERS | 2004年 / 387卷 / 4-6期

关键词：

D O I：

10.1016/j.cplett.2004.02.053

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

A novel mechanism of charge separation in a dimer of two-orbital molecular system is proposed. The effective electron-electron repulsive energy in the dimer, U-eff, has been estimated by means of valence-bond (VB) model calculations for the ground state of the dimer. It has been found that the HOMO-LUMO interplay leads to negative U-eff in the strong dimerization condition, indicating spontaneous separation of charges on dimers (2 dimer(-) --> dimer(0) + dimer(2-)). Possible relevance to experimental features in some [Pd(dmit)(2)] salts (dmit = 1,3-dithiol-2-thione-4,5-dithiolate) is discussed. (C) 2004 Elsevier B.V. All rights reserved.

引用

页码：448 / 452

页数：5

共 17 条

[1]

Canadell E, 1997, NEW J CHEM, V21, P1147

[2] ON THE BAND ELECTRONIC-STRUCTURE OF X[M(DMIT)2]2 (X=TTF, (CH3)4N - M=NI, PD) MOLECULAR CONDUCTORS AND SUPERCONDUCTORS [J].

CANADELL, E ;

RACHIDI, IEI ;

RAVY, S ;

POUGET, JP ;

BROSSARD, L ;

LEGROS, JP .

JOURNAL DE PHYSIQUE, 1989, 50 (19) :2967-2981

[3] Recent progress in NMR studies on organic conductors [J].

Kanoda, K .

HYPERFINE INTERACTIONS, 1997, 104 (1-4) :235-249

[4]

Kato R, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.020508

[5]

Kobayashi A, 2001, J MATER CHEM, V11, P2078, DOI 10.1039/b102865k

[6] First-principles study of the electronic structure of the organic solids (CH3)4N[M(dmit)2]2 (M = Ni and Pd):: Role of dimerization and the stability of the formation of a dimer [J].

Miyazaki, T ;

Ohno, T .

PHYSICAL REVIEW B, 1999, 59 (08) :R5269-R5272

[7]

Mori M, 2000, MOL CRYST LIQ CRYST, V343, P539

[8] Estimation of off-site Coulomb integrals and phase diagrams of charge ordered states in the θ-phase organic conductors [J].

Mori, T .

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 2000, 73 (10) :2243-2253

[9] Non-stripe charge order in the θ-phase organic conductors [J].

Mori, T .

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2003, 72 (06) :1469-1475

[10] Structural properties of M(dmit)2-based (M = Ni, Pd, Pt; dmit2- equals 2-thioxo-1,3-dithiole-4,5-dithiolato) molecular metals.: Insights from density functional calculations [J].

Rosa, A ;

Ricciardi, G ;

Baerends, EJ .

INORGANIC CHEMISTRY, 1998, 37 (06) :1368-1379

← 1 2 →