The 1-D Hubbard Model With Alternating Crystal Potential Comparision With Experiments on DMM-TCBQ2

Abstract In this paper some properties are calculated of a quarter filled Hubbard band, where an extra term is added to the Hamiltonian, which describes the donor chain induced potential on the electron chain. Both exact and numerical results are presented. For DMM-TCNQ2 we conclude that the potential difference between adjacent sites is approximately four times the transferin-tegral. At low temperature the magnetic exchange is observed to be strongly temperature dependent, for which a mechanism is suggested.