Ruddlesden‐Popper (R‐P) type compounds in the parent La‐Cu‐O system have been reported to exist up to then=7 series member of Lan+1CunO3n+1[1]. La2CuO4is the first member of the series and LaCuO3, then=∞ member. The other members of the series can be regarded as combinations of these two end members.The crystal structure of La2CuO4has been well characterized but the structural information of the other members of this series is lacking in the literature. An atomistic computer simulation was performed to predict the equilibrium structures for the first five members of this series. XRD patterns were then calculated to aid in analyzing the experimentally prepared samples of higher order phases.The ability to synthesize structurally stable bulk compounds of the Lan+1CunO3n+1homologous series using a solid state and nitrate preparation technique has been investigated. Samples with starting stoichiometries corresponding to series members were reacted in both air and oxygen atmospheres. Results indicate bulk structural instability of series members higher thann=1.