This experiment is concerned with the response of a high-dielectric constant metal-organic framework (MOF), lead(II) tricyanomethanide, Pb(tcm)2 to applied electric fields. Crystallising in the (rare) polar space group P31m and showing large structural changes with temperature, Pb(tcm) is a promising candidate for understanding MOF ferroelectrics and, more generally, the response of coordination polymers to applied fields. In order to design related phases with superior (ferroelectric) properties we need an understanding of the structural changes that occur in Pb(tcm)2 under applied electric fields e.g. is the mechanism of flexibility activated by temperature also activated by applied field? The measured cell parameters and atomic coordinates will allow us to couple our experiment with ab-initio electron density calculations, from which crystal polarisations can then be determined.