The neutron diffraction pattern of a single crystal of cubic NaCN has been measured at 295deg;K. These data and earlier results for KCN at 180 and 295deg;K have been analyzed in terms of a model which expands the angular distribution of CNminus;orientations in symmetryhyphen;adapted spherical harmonics. From this analysis, the distributions of CNminus;in these crystals have been derived, and these indicate a monotonic trend in the series KCN (295deg;K) thru KCN (180deg;K) to NaCN (295deg;K) involving a shift in preferential orientation from the 111 toward the 100 directions in the crystal. Unusually large translational Debyehyphen;Waller factors have also been derived for NaCN and KCN from the fitting procedure, in agreement with earlier results and analysis on KCN. In addition, an averageCtrpbnd;Nbond distance of 1.18 Aring; is obtained.
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