  Structural and electronic properties of ferroelectric columnar clusters
constructed from benzene-1,3,5-tricarboxylic acid, (B3CA)n, were investigated
at the Hartree-Fock level. It is shown that B3CA stacks form helix-shaped
molecular tubes which are stabilized by intermolecular hydrogen bonds. It is
furthermore shown that the strong electric field generated by the uniaxial
alignment of the carboxyl groups can split an optically prepared exciton into
an electron-hole pair and can drive the charge carriers to the opposite ends of
the tube. Some consequences of the phenomenon for photovoltaic applications are
discussed.
