  We present a recently developed one-dimensional dipole lattice model that
accurately captures the key properties of water in narrow nanopores. For this
model, we derive three equivalent representations of the Hamiltonian that
together yield a transparent physical picture of the energetics of the water
chain and permit efficient computer simulations. In the charge representation,
the Hamiltonian consists of nearest-neighbor interactions and Coulomb-like
interactions of effective charges at the ends of dipole ordered segments.
Approximations based on the charge picture shed light on the influence of the
Coulomb-like interactions on the structure of nanopore water. We use Monte
Carlo simulations to study the system behavior of the full Hamiltonian and its
approximations as a function of chemical potential and system size and
investigate the bimodal character of the density distribution occurring at
small system sizes.
