The position, full-width at half-maximum (FWHM) and area of the C-C, C-N and Mn-N correlations were fitted using a Gaussian Please do not adjust margins Please do not adjust margins function. The proximity of the C-C (2.45 Å) and C-N (2.57 Å) correlations to that for Mn-N (2.22 Å), rendered it necessary to fit the experimental peak using multiple peak fitting. Regression analysis is shown in Fig. and the extracted parameters are tabulated in Table . The substantial contribution of instrumental broadening to the peaks (2π/Qmax = 0.29 Å) dominates the measurements, and, combined with correlations in the fitting parameters from overlapping peaks, direct links to the Lindemann criterion for melting could not be made. Nevertheless, the temperature variation of the FWHM, peak positions and areas at the melting point clearly show marked changes, which may be consistent with a melting process involving Mn-N bond breakage and some thermal decomposition of both organic species (Fig. ). A similar analysis for [TPnA][Mn(dca)3] (Fig. ) was carried out and is also suggestive of changes at Tm.