Solubilities of the staturated solution of quarternary systems of CsCl-NdCl~3-13%HCl-H~2O and CsCl-NdCl~3-42%HOAc-H~2O were studied at 25℃. The corresponding equilibrium diagrams were constructed. New compounds of 2:1 type and 1:1 type were discovered in the investigated systems. The discovery of new compounds gives out phase foundation for synthesizing the corresponding compounds using Meyer's method. In the investigated systems the "equal medium effect" for HCl and HOAc was found.

Key words: QUATERNARY SYSTEM, NEODYMIUM CHLORINE, CESIUM CHLORIDE, MEDIUM EFFECT, PHASE EQUILIBRIUM, COMPOUND CHARACTERIZATION