Quadruple-layered perovskite (CuCl)Ca2NaNb4O13

► (CuCl)Ca2NaNb4O13 was prepared by ion-exchange reaction of RbCa2NaNb4O13 with CuCl2. ► Compound has a 2ap×2ap×2cp superstructure (tetragonal; a=7.73 Å, c=39.21 Å). ► Such a well-defined superstructure was not observed in the precursor compound. ► Aleksandrov′s theory and Rietveld study suggest a (++0) octahedral tilting (I4/mmm). ► Magnetic studies revealed the absence of magnetic order down to 2 K.