Ground-state electronic properties of the charge transfer molecular crystal NMP-TCNQ. I. One-dimensional treatment including electron correlation

Abstract

The Pariser-Parr-Pople Hamiltonian is used within the framework of the restricted and unrestricted Hartree-Fock crystal orbital methods to compute the energy-band structures, charge and spin density distributions in the one-dimensional TCNQ- columns of the NMP-TCNQ crystal. As a consequence of electronic correlation effects the ground state of the system is shown to be a magnetic insulator. Different mechanisms which reduce the interelectronic repulsion in organic systems are discussed and the possibility of the application of a simple Hubbard-type Hamiltonian to molecular crystals is investigated.