Abstract The structure of an A cation-deficient pyrochlore (K, Bi)⋍ 1.5 Bi 2 O∼ 6 (H 2 O)∼ 1 has been investigated by powder neutron diffraction using a deuterated sample. Main results of previous X-ray work are confirmed: 25% of A sites are empty; only a small amount of oxygen is found in 8 (b) positions, a greater proportion being located in 32 (e) positions which are displaced toward the A vacancy. The latter oxygen atoms belongs to a heavy ...
