  Using a combination of Rietveld and RMC refinement of neutron total
scattering data, we find that the 10 K structure of zinc(II) isonicotinate
shows strong evidence of static disorder. This disorder takes the form of
transverse displacements of the isonicotinate ligand and results in elongated
atomic displacement parameters and dampened oscillations of the experimental
G(r). We analyse the RMC configurations using an approach derived from
geometric algebra. Complications regarding the inclusion of hydrogenous guest
molecules within the pore structure are discussed. This study highlights the
way in which structural flexibility can give rise to multiple low-energy ground
states in MOF-type materials.
