CA2RHH5.4 - STRUCTURE DETERMINATION VIA NEUTRON-DIFFRACTION EXPERIMENTS

The structure of Ca2RhH5 described by Moyer et al. is only known respe ctive to the arrangement of the metal atoms. Elastic neutron diffracti on experiments on the deuterated compound led to the complete structur e, which corresponds to that of the K2PtCl6 type structure with the ch loride sites statistically occupied in accordance with the formula of the mixed valent compound Ca2RhD5.4. A neutron diffraction diagram of a high resolution T-O-F spectrometer led to the up to now unknown comp ound Ca8Rh5D23 which crystallises isotypic to the analogous strontium compound in an atomic arrangement representing a transition from the K 2PtCl6 type to the perovskite type structure.