  Charge transport in two zinc metal-organic frameworks (MOFs) has been
investigated using periodic semiempirical molecular orbital calculations with
the AM1* Hamiltonian. Restricted Hartree-Fock calculations underestimate the
band gap (Koopmans theorem), which however becomes more realistic when the
wavefunction is allowed to become unrestricted. Charge-transport simulations
using propagation of the electron- or hole-density in imaginary time allow
charge-transport paths to be determined, although the calculated mobilities
must still be improved. In general, the techniques discussed appear to be
useful for investigating electroactive MOFs.
