Question A3 Cesium hydride, CsH, has the cesium chloride structure with unit cell parameter a = 3.82 Å. a) Calculate the Coulomb (ionic) energy of CsH, assuming that the ions have their formal charges Cs and H. Give your answer in kJ mol-1. b) A neutron diffraction pattern was measured from a powder sample of this material. The neutron scattering length of Cs is 5.42 fm and of H is -3.74 fm. Calculate the structure factor and multiplicity of (i) the (200) diffraction peak; and (ii) the (210) diffraction peak. Hence (iii) estimate the ratio of the intensity of the (200) to the (210) peak in the diffraction pattern.

Question A3 Cesium hydride, CsH, has the cesium chloride structure with unit cell parameter a = 3.82 Å. a) Calculate the Coulomb (ionic) energy of CsH, assuming that the ions have their formal charges Cs and H. Give your answer in kJ mol-1. b) A neutron diffraction pattern was measured from a powder sample of this material. The neutron scattering length of Cs is 5.42 fm and of H is -3.74 fm. Calculate the structure factor and multiplicity of (i) the (200) diffraction peak; and (ii) the (210) diffraction peak. Hence (iii) estimate the ratio of the intensity of the (200) to the (210) peak in the diffraction pattern.