Inelastic Neutron Scattering Spectra and Raman Spectra of CsHCl2 and CsDCl2

This paper describes the use of neutron inelastic scattering data and Raman spectral data on CsHCl₂ and CsDCl₂, in conjunction with earlier infrared data, to confirm the noncentrosymmetric nature of the bichloride ion in these salts. The inelastic neutron scattering data eliminates $D_{\mathrm{\infty h}}$ as the point group of the ion and the Raman data shows that the ion is bent, so that the ion belongs either to the point group C_2υ or C_s. Reinterpretation of the infrared spectra suggests that the bending vibration in the ion is split by dynamical tunneling between the two possible bent configurations.