title: CuCN: a polymorphic material. Structure of one form determined from total neutron diffraction.
abstract: CuCN has been found to be polymorphic. The structure of one form, which is isomorphous with AgCN, has been determined using the information provided by Bragg and diffuse neutron scattering. The polymorph of CuCN formed has been found to depend on the Cu/CN ratio used in its preparation.