1998 年度実績報告書

集積型金属錯体の電子構造理論

研究課題

研究課題/領域番号	10149105
研究機関	大阪大学
研究代表者	山口兆大阪大学, 大学院・理学研究科, 教授 (80029537)
研究分担者	米満賢治岡崎国立共同研究機構, 分子科学研究所, 助教授 (60270823) 古賀伸明名古屋大学, 人間情報学部, 助教授 (80186650) 川村尚岐阜大学, 工学部, 教授 (40026125)
キーワード	分子磁性の理論 / ab initio計算 / 有効交換積分 / 量子トンネル効果 / 光誘起強磁性 / 量子位相ダイナミックス
研究概要	(1) 開殻分子クラスターのab initio計算本研究では、まず始めに有効交換積分(J_<ab>値)をab initio計算により先験的に求める方法について検討した.そのため、N個の開殻分子の一次元クラスター(分子間距離を等間隔と仮定)を考え、構成分子間のJ_<ab>値を1最低スピン(lowest spin;LS)と最高スピン(highest spin;HS)状態間のab initio法による全エネルギー差より計算する手法を開発した。例えば、クラスターとして、水素原子(H)_<20〜100>、三重項メチレン等(X)_<11>(X=CH_2,N,etc)、リチウム等(X)_<11>(X=Li,CU,etc)、2価モリブデン(X)_<2〜5>(X=Mo(II),Cr(II))を取り上げ、非制限ハートリーフォック(UHF)法および非制限密度汎関数(DFT)法によりHSとLS状態の全エネルギーとJ_<ab>値を求めた。例えば11サイトを持つ三重項CH,の平行(//)および垂直型(〓)積層クラスター、四重項窒素原子クラスター、およびCH_2、Nの交互積層クラスターにおけるJ_<ab>値を計算した。\|J_<ab>\|値はサイト間距離(R)の増加とともに指数関数的に減少するが、その符号は一定であることがわかる。また、Rが短くなるとラジカル軌道間の重なり効果(B3LYPとAPB3LYPの差)を無視できない。DFT(B3LYP.APB3LYP)法による\|J_<ab>\|値はUHFMP2(UMP2)法による値より大きくなる傾向を示した. (2)二核遷移金属錯体における有効交換相互作用二核クロムアセテート錯体Cr_2(O_2CCH_3)_4(H_2O)_2(1)のX線構造を仮定してJ_<ab>値のab initio DFT計算を実行し、その有効性を検討することにした。まず交換相関ポテンシャルEx化して、その混合比(Ci)を変えてJ_<ab>値を求めた.BLYP法は\|J_<ab>\|値を実測値に比較して過大に評価しすぎる傾向を示し、B3LYP法でも、その傾向は完全には修正されない。これは、△E(B88〉項がスピン非局在化に大きく寄与するためである。一方、その寄与を小さくしたB2VWN-法では実験によるJ_<ab>を完全に再現した。一方Prussian Blue化合物の二核クラスターモデル(2)ではB3LYP法で実測値が再現されている。

研究成果
(18件)

すべてその他

すべて文献書誌 (18件)

[文献書誌] M.Nishino: "Switching dynamics between the metastable ordered magnetic state and a nonmagnetic ground state : A possible mechanism for photoinduced ferromagnetism" Phys.Rev.B58. 9303-9311 (1998)
[文献書誌] H.Nagao: "Possibility of Charge-mediated superconductors in the intermedtated region of metal-insulator transitions" Int.J.Quantum.Chem.70. 1075-1084 (1998)
[文献書誌] A.Okamura: "Electronic structures of organometallic conjugated systems. Possibilities of molecular magnets,magnetic conductors and spin-mediated superconductors composed of metallocene units" J.Organometallic Chemistry.569. 177-187 (1998)
[文献書誌] M.Nishino: "Effective exchange interactions and magnetic phase transition temperatures in Prussian blue analogs : A study by density functional theory" Chem.Phys.Letters.295. 328-336 (1998)
[文献書誌] M.Nakano: "Quasiprobability distribution dynamics of an initially one-mode coherent photon field interacting with two-and three-state molecule systems" Chem.Phys.Letters.295. 317-327 (1998)
[文献書誌] T.Kawakami: "Theoretical study of electronic structures of one-dimensional magnetic clusters composed of doublet lithium and copper atoms" J.Mol.Structure.(Theochem). 451. 89-107 (1998)
[文献書誌] S.Takamizawa: "The gas-occlusion properties of dicarboxylate(fumarate,trans-trans-muconate and terephthalate)ruthenium(II,III)dinuclear complexes" Inorg.Chemistry Commn.1. 177-178 (1998)
[文献書誌] K.Yamaguchi: "Ab Initio Size-Consistent Calculations of Effective Exchange Interactions in Mesoscopic Magnetic Clusters Composed of Triplet Methylenes and Quartet Nitrogen Atoms" Bull.Chem.Soc.Jpn. 71. 2097-2108 (1998)
[文献書誌] Y.Yoshioka: "Hubbard and Heisenberg Models fo Four-Site Four-Electron Systems. Group Theoretical Interrelationships and Applications to Multicenter Transition Metal Clusters" Bull.Chem.Soc.Jpn. 71. 573-588 (1998)
[文献書誌] M.Nishino: "Theoretical Studies of Multiple Metal-Metal Bonds between Divalent Molybdenum Ions in Dimers,Tetramers and Clusters" Bull.Chem.Soc.Jpn. 71. 99-112 (1998)
[文献書誌] M.Nakano: "Numerical couple Liouville approach : dependence of population differences between excited and ground states on field intensity and size of molecular aggregates" Chem.Phys.Letters. 288. 25-32 (1998)
[文献書誌] T.Kawamura: "Geometrical Difference and Electron Configuration of Lantern-Type Rh^<1+>_2 and Th^<5+>_2 Complexes : X-Ray SStructural and DFT Studey." J.Am.Chem.Soc. 120. 8136-8142 (1998)
[文献書誌] Zhiyong Yang: "Bis[dirhodium(II)]Compoex with Rh_4(μ_2-Cl)_4Core : Preparation and Characterization." J.Chem.Soc.,Dalton Trans. 2277-2278 (1998)
[文献書誌] Jun-ichiro Kishine: "Dimensional Crossovers in the Doped Ladder System : Spin Gap,Superconductvity and Interladder Coherent Band Motion." J.Phys.Soc.Jpn. 67. 1714-1731 (1998)
[文献書誌] Jun-ichiro Kishine: "Antiferromagnetic Phase Transition and Crossover to Fermi Liquid Phase in a Weakly Corpled Half-Filled Chain System." J.Phys.Soc.Jpn. 67. 2590-2593 (1998)
[文献書誌] Yutaka Imamura: "Theoretical Study on Electron Correlation of 1-D(DCNQI)_2M(M=Li,Ag)Salts." Chem.Phys.Lett.298. 15-20 (1998)
[文献書誌] Jun-ichiro Kishine: "One-Particle vs Two-Particle Crossover in Weakly Coupled Hubbaard Chains and Ladders : Perturbative Penormalization Group Approach." Proceedings of the 9th Internatioal Conference on Recent Progress in Many-Body Theories. 1. 490-492 (1998)
[文献書誌] Kenji Yonemitsu: "Superconductibity and Magnetism in Quasi-One-Dimensional Two-Bamd Systems." Rev.High Pressure. 1. 408-412 (1998)

1998 年度 実績報告書

集積型金属錯体の電子構造理論

研究代表者

山口 兆 大阪大学, 大学院・理学研究科, 教授 (80029537)

研究成果

[文献書誌] M.Nishino: "Switching dynamics between the metastable ordered magnetic state and a nonmagnetic ground state : A possible mechanism for photoinduced ferromagnetism" Phys.Rev.B58. 9303-9311 (1998)

[文献書誌] H.Nagao: "Possibility of Charge-mediated superconductors in the intermedtated region of metal-insulator transitions" Int.J.Quantum.Chem.70. 1075-1084 (1998)

[文献書誌] A.Okamura: "Electronic structures of organometallic conjugated systems. Possibilities of molecular magnets,magnetic conductors and spin-mediated superconductors composed of metallocene units" J.Organometallic Chemistry.569. 177-187 (1998)

[文献書誌] M.Nishino: "Effective exchange interactions and magnetic phase transition temperatures in Prussian blue analogs : A study by density functional theory" Chem.Phys.Letters.295. 328-336 (1998)

[文献書誌] M.Nakano: "Quasiprobability distribution dynamics of an initially one-mode coherent photon field interacting with two-and three-state molecule systems" Chem.Phys.Letters.295. 317-327 (1998)

[文献書誌] T.Kawakami: "Theoretical study of electronic structures of one-dimensional magnetic clusters composed of doublet lithium and copper atoms" J.Mol.Structure.(Theochem). 451. 89-107 (1998)

[文献書誌] S.Takamizawa: "The gas-occlusion properties of dicarboxylate(fumarate,trans-trans-muconate and terephthalate)ruthenium(II,III)dinuclear complexes" Inorg.Chemistry Commn.1. 177-178 (1998)

[文献書誌] K.Yamaguchi: "Ab Initio Size-Consistent Calculations of Effective Exchange Interactions in Mesoscopic Magnetic Clusters Composed of Triplet Methylenes and Quartet Nitrogen Atoms" Bull.Chem.Soc.Jpn. 71. 2097-2108 (1998)

[文献書誌] Y.Yoshioka: "Hubbard and Heisenberg Models fo Four-Site Four-Electron Systems. Group Theoretical Interrelationships and Applications to Multicenter Transition Metal Clusters" Bull.Chem.Soc.Jpn. 71. 573-588 (1998)

[文献書誌] M.Nishino: "Theoretical Studies of Multiple Metal-Metal Bonds between Divalent Molybdenum Ions in Dimers,Tetramers and Clusters" Bull.Chem.Soc.Jpn. 71. 99-112 (1998)

[文献書誌] M.Nakano: "Numerical couple Liouville approach : dependence of population differences between excited and ground states on field intensity and size of molecular aggregates" Chem.Phys.Letters. 288. 25-32 (1998)

[文献書誌] T.Kawamura: "Geometrical Difference and Electron Configuration of Lantern-Type Rh^<1+>_2 and Th^<5+>_2 Complexes : X-Ray SStructural and DFT Studey." J.Am.Chem.Soc. 120. 8136-8142 (1998)

[文献書誌] Zhiyong Yang: "Bis[dirhodium(II)]Compoex with Rh_4(μ_2-Cl)_4Core : Preparation and Characterization." J.Chem.Soc.,Dalton Trans. 2277-2278 (1998)

[文献書誌] Jun-ichiro Kishine: "Dimensional Crossovers in the Doped Ladder System : Spin Gap,Superconductvity and Interladder Coherent Band Motion." J.Phys.Soc.Jpn. 67. 1714-1731 (1998)

[文献書誌] Jun-ichiro Kishine: "Antiferromagnetic Phase Transition and Crossover to Fermi Liquid Phase in a Weakly Corpled Half-Filled Chain System." J.Phys.Soc.Jpn. 67. 2590-2593 (1998)

[文献書誌] Yutaka Imamura: "Theoretical Study on Electron Correlation of 1-D(DCNQI)_2M(M=Li,Ag)Salts." Chem.Phys.Lett.298. 15-20 (1998)

[文献書誌] Jun-ichiro Kishine: "One-Particle vs Two-Particle Crossover in Weakly Coupled Hubbaard Chains and Ladders : Perturbative Penormalization Group Approach." Proceedings of the 9th Internatioal Conference on Recent Progress in Many-Body Theories. 1. 490-492 (1998)

[文献書誌] Kenji Yonemitsu: "Superconductibity and Magnetism in Quasi-One-Dimensional Two-Bamd Systems." Rev.High Pressure. 1. 408-412 (1998)

1998 年度実績報告書

山口兆大阪大学, 大学院・理学研究科, 教授 (80029537)