Peierls-Hubbard Hamiltonian

The Peierls-Hubbard Hamiltonian, which considers both e-e and e-p correlations explicitly, is given by ... 

Tight-binding approximation (TBA) Hiickel-Hubbard Hamiltonian Hopping integral t Peierls distortion Magnetic material Nonmagnetic material... 

Group method was applied for dynamic aL and yL using ID Hubbard and U-V models and a Hubbard-Peierls model Hamiltonian in the case of linear polyenes. 

The symmetrized Density Matrix Renormalisation Group Procedure145 using a Hubbard-Peierls model Hamiltonian has given for a linear polyene chain quite satisfactory results for aL(static) and for yL(coa co, co2, ) (coa = co + a>2 + ) and for (yL/jV)(static). 

Outline the major features, strong points and drawbacks of the following theoretical methods EH VEH methods using the SSH Hamiltonian methods using Pariser-Parr-Pople type Hamiltonians methods using Peierls-Hubbard type Hamiltonians. 

The Hubbard model, which has played a significant part in the earlier development of nonlinear optical response theory of molecules, has been revived by Shehadi et al.203 to explain the properties of small bridged metallic polymers. The Hubbard-Peierls hamiltonian has also been used by Shuai et al.,204 in conjunction with a symmetry adapted density matrix renormalization group formulation, to calculate a number of properties, including third harmonic generation in trans-octatetraene. 

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