(Ca(x)Nd(11-x))Ru(4)O(24) (x = 4.175).

Single crystals of the title compound, calcium neodymium ruthenate, (Ca(x)Nd(11-x))Ru(4)O(24) (x = 4.175), have been grown by the flux method. The structure consists of two crystallographically independent RuO(6) octa-hedra, which are isolated from each other and embedded in a matrix composed of the Ca and Nd atoms. There are seven M sites which accommodate the Ca and Nd atoms with different populations. Four M sites at general positions are enriched with Nd, whereas the remaining three M sites on twofold rotation axes are enriched with Ca. The coordination numbers of O atoms to the M sites range from 6 to 9. The mean oxidation state of Ru was estimated at +4.79 from the composition analysis. The title compound is non-centrosymmetric and potentially multiferroic.