Аннотация:The rare-earth phosphide carbides RE4[P1-x(C-2)(x)](3) (RE= La, Ce, Pr, Nd) represent the first example of a mixed anionic substructure formed by phosphorus and carbon, being the first step toward the formation of the mixed inorganic P-C species. The peculiarities of the crystal structure, magnetic properties, XAS data, and quantum chemical calculation results confirm the ionic nature of the interaction between the rare-earth cations RE and phosphorus anions, while complex interaction of pi states of the C-2 anions and d (and/or f) states of the RE components is indicated. Thus, despite the extensive chemical analogy between the phosphide carbides and phosphide silicides, the atomic interactions stabilizing the structural motif are slightly different.