PMID- 19908878
OWN - NLM
STAT- MEDLINE
DCOM- 20100301
LR  - 20131121
IS  - 1520-5215 (Electronic)
IS  - 1089-5639 (Linking)
VI  - 113
IP  - 52
DP  - 2009 Dec 31
TI  - Symmetry and broken-symmetry in molecular orbital descriptions of unstable 
      molecules. 3. The nature of chemical bonds of spin frustrated systems.
PG  - 15281-97
LID - 10.1021/jp905991r [doi]
AB  - Symmetry and broken symmetry in the molecular orbital description of spin 
      frustration systems have been investigated in relation to the resonating valence 
      bond (RVB) theory of the spin liquid state and non-BCS superconductivity. Broken 
      symmetry (BS) and resonating BS (RBS) molecular orbital (MO) methods have been 
      employed to obtain resonating valence bond (RVB)-type explanations of spin 
      frustrated systems. RBS MO solutions are expanded using the localized molecular 
      orbitals (LMO) to elucidate a universal MO-VB description. The BS and RBS MO 
      descriptions of triangular spin frustrated systems corresponding to transition 
      structures for exchange-forbidden radical insertions were investigated in 
      comparison with the RVB-type explanations of such systems. The BS and RBS 
      calculations by the use of three different axial (SDW) solutions or three 
      noncollinear GSO (helical SDW) solutions of a triangular hydrogen cluster were 
      performed to obtain potential curves with and without resonance (quantum) 
      effects. The resonating GSO (noncollinear) state responsible for short-range 
      correlation was found to be the most stable for the system. The reliability of 
      the approximate spin projection (AP) procedure to eliminate the high-spin 
      component was also elucidated, comparing with the AP BS and RBS potential curves. 
      The BS GSO (GHF) computations of several triangular systems, N(CH(2))(3), 
      (CH(2))(3), and Mn(II)(3)O(4), were performed to obtain total energies and total 
      spin angular momentums and effective exchange integrals (J) between local spins, 
      which are crucial for construction of effective spin Hamiltonian models. The 
      exact diagonalization of the Heisenberg models was also performed to depict the 
      energy levels and magnetic susceptibility curves for triangular and kagome 
      lattices to elucidate spin frustration effects and related quantum spin 
      behaviors. Implications of the computational results have been discussed in 
      relation to magnetic properties of several triangular and kagome systems 
      synthesized recently and the superconductivity of triangular systems discovered 
      recently.
FAU - Kawakami, T
AU  - Kawakami T
AD  - Department of Chemistry, Graduate School of Science, Osaka University, 1-1 
      Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
FAU - Takeda, R
AU  - Takeda R
FAU - Nishihara, S
AU  - Nishihara S
FAU - Saito, T
AU  - Saito T
FAU - Shoji, M
AU  - Shoji M
FAU - Yamada, S
AU  - Yamada S
FAU - Yamanaka, S
AU  - Yamanaka S
FAU - Kitagawa, Y
AU  - Kitagawa Y
FAU - Okumura, M
AU  - Okumura M
FAU - Yamaguchi, K
AU  - Yamaguchi K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Phys Chem A
JT  - The journal of physical chemistry. A
JID - 9890903
RN  - 0 (Amines)
RN  - 0 (Transition Elements)
RN  - 7YNJ3PO35Z (Hydrogen)
RN  - J64922108F (Benzene)
SB  - IM
MH  - Amines/chemistry
MH  - Benzene/chemistry
MH  - Hydrogen/chemistry
MH  - Models, Molecular
MH  - Molecular Conformation
MH  - *Quantum Theory
MH  - Transition Elements/chemistry
EDAT- 2009/11/17 06:00
MHDA- 2010/03/02 06:00
CRDT- 2009/11/14 06:00
PHST- 2009/11/14 06:00 [entrez]
PHST- 2009/11/17 06:00 [pubmed]
PHST- 2010/03/02 06:00 [medline]
AID - 10.1021/jp905991r [doi]
PST - ppublish
SO  - J Phys Chem A. 2009 Dec 31;113(52):15281-97. doi: 10.1021/jp905991r.