NEUTRON POWDER DIFFRACTION INVESTIGATIONS OF PURE AND DEUTERATED TI3PO0.58

The crystal structures of Ti3PO0.58 and Ti3PO0.58D0.37 have been refin ed from neutron powder diffraction room temperature data using the Rie tveld method. Ti3PO0.58 crystallizes in the filled Re3B type structure , space group Cmcm, with the unit cell dimensions a=3.2934(2) Angstrom , b=9.8978(6) Angstrom and c=7.7143(4) Angstrom, Z=4. The dissolved de uterium atoms in Ti3PO0.58D0.37 occupy two different types of intersti ces between the metal atoms, one position octahedrally surrounded by s ix titanium atoms and one position with four close titanium neighbours in a tetrahedral arrangement. The unit cell dimensions increase to a= 3.2975(5) Angstrom, b=9.9028(9) Angstrom and c=7.7596(8) Angstrom.