Theoretical study on electron correlation of 1-D (DCNQI)2M (M=Li, Ag) salts

We study electronic states of the (DCNQI)2M (M=Li and Ag) salts based on the full configuration interaction (FCI) method using effective Hamiltonians derived from ab initio molecular orbital theory. FCI results of the DCNQI tetramer and octamer models indicate that the ground state has antiferromagnetic and charge ordering correlations. It corresponds to the 2kF spin density wave and 4kF charge density wave states (SDW and CDW, respectively). In the octamer model, it is also found that some low-lying excited states have similar spin-flipped CDW correlations and the antiferromagnetic correlation is weakened.